View Full Version : Relevance of intermediate rounds such as 6.8 under 'new' paradigm?
In the older school of thought that favored fragmenting 5.56 rounds for all-purpose defensive loadings, the advantages of calibers such as the 6.8 were concrete and significant.
A) Fragmentation was the key to ideal wounding, and fragmentation range increased dramatically with the larger calibers at a given barrel length.
B) Larger calibers such as 6.8 SPC defeated barriers that OTM and FMJ 5.56 rounds could not.
The new thinking seems to be that barrier blind 5.56 rounds such as BH 50 grain TSX should be employed for general use. They maintain ballistic performance out to 300 yards, which largely negates the range issue. They also defeat commonly encountered barriers, unlike their OTM and FMJ cousins.
If we accept that their terminal performance (expansion to ~.45" and a large, consistent, early-forming temporary cavity that wounds inelastic and fluid filled organs such as the heart, kidneys, and liver) is adequate without fragmentation, is there much of a point to larger calibers such as the 6.8 anymore? Or has this become more of a marginal, incremental paradigm such as the 9mm vs. .40 S&W vs. .45 ACP?
Hmm. Interesting theory. Id be inclined to believe that with good barrier blind loads that the slightly larger intermediate sized cartridges dont offer much over the 5.56.
Intermediate calibers (6.5-7mm) with well designed barrier blind loads are substantially MORE impressive than any 5.56 mm load...
Intermediate calibers (6.5-7mm) with well designed barrier blind loads are substantially MORE impressive than any 5.56 mm load...
Is the siren song of the 7.62x51 again beckoning? I'm getting another headache.
Is the siren song of the 7.62x51 again beckoning? I'm getting another headache.
Intermediate calibers that fit the AR15 magwell do not exact the carry weight penalty of .308 ammo (not even close) and obviously do not need the heavier and larger AR10/SR25 platform.
Intermediate calibers that fit the AR15 magwell do not exact the carry weight penalty of .308 ammo (not even close) and obviously do not need the heavier and larger AR10/SR25 platform.
+1
dont forget that the 6.8 also has extended the effective range of the carbine as well as the terminal ballistics.
better 5.56 bullets are really just a patch for it's inherent deficiencies. It works, but it's still subject to the laws of physics and momentum. Heavier, still breaks thru stuff better.
Microalign
12-23-11, 15:20
I've been debating this myself. By all means of measurement, ie terminal effects and barrier testing, the 6.8 is superior to the 5.56 in every way, and is a much more manageable carbine choice over the .308. It is just unfortunately that the 6.8 lacks any wide spread adoption. I would also like to see a lower receiver specifically designed for the 6.8 so that the magazine well can be wider and accomidate magazines on par with PMAGs instead of the thin steel walled magazines available now.
+1
dont forget that the 6.8 also has extended the effective range of the carbine as well as the terminal ballistics.
better 5.56 bullets are really just a patch for it's inherent deficiencies. It works, but it's still subject to the laws of physics and momentum. Heavier, still breaks thru stuff better.
Lets not forget that the 6.8 is in itself a patch which operates within the limitations of the AR-15 platform. If we had something like an AR-12.5 that provided a longer magazine well, and action than the AR-15, but still shorter than the AR-10 we could start getting rifles that are optimized for the 7 X 46mm and other true intermediate cartridges.
Considering all the gear many people hang off an AR-15 a naked AR-10 like a Larue PredatAR .308 doesn't really weigh any more. As far as ammunition goes I don't see ammo weight being an issue for civilian or even LE tactical usage. The tradeoff between firepower, and mobility is always a consideration. .308 still holds a significant advantage over any of the other common service rifle calibers as far as terminal performance, and intermediate barrier performance. The user must of course determine if the added recoil, weight, and expense is worth the increase.
Gee...which one is likely to be more effective at incapacitating an aggressive violent opponent?
http://www.tridentconcepts.com/alumni/Portals/0/NTForums_Attach/1823542651571.jpg
Intermediate calibers (6.5-7mm) with well designed barrier blind loads are substantially MORE impressive than any 5.56 mm load...
This is also backed up by TONS of non-scientific real use evidence as well.
Chris L (HTR) has taken over 400 hogs with nearly every available combination of loads in both 5.56 and 6.8.
Hogs are tough. They are practically a walking barrier of bone and mean.
His summary is that the 5.56 would drop them with a single shot around half the time.
In other words, inconsistent terminal performance.
With the 6.8, single shot drops are closer to 9 out of 10.
Gee...which one is likely to be more effective at incapacitating an aggressive violent opponent?
Doc,
I think I mentioned this before... A review the ballistic gel data on Hornady's LE website shows almost identical performance between the TAP 6.8 110 BTHP and the .308 155 gr TAP while the 168 gr BTHP is worse than both previously mentioned.
http://hornadyle.com/products/more_detail0a5d.html?id=72&sID=151&pID=1
http://hornadyle.com/products/more_detail14c6.html?id=72&sID=79&pID=2
While the 6.8 mm 110 gr OTM offers excellent terminal performance that is better than any 5.56 mm load, the 155 gr TAP in those links is creating a substantially larger wound track than the 6.8 mm.
If that's the "new paradigm" I'd abandon 5.56NATO tomorrow. Fortunately, it sounds like a temporary fad that shouldn't last too long.
One of the big selling points, in my opinion, on the 5.56NATO cartridge is that it has excellent terminal performance on a "primary target" (the person you are exchanging fire with) but has a reduced risk of stray rounds penetrating through common materials and putting innocent bystanders at risk.
The other big selling point on the 5.56NATO is the fragmentation it exhibits in tissue. It is a very effective cartridge at causing damage to the human body.
For law enforcement and the defense-minded citizen this is an advantage. Obviously, your trade-off is that you lose some ability to penetrate barriers that your opponent may be using as cover or concealment.
To me, losing the two biggest advantages of the 5.56NATO to basically revert to a glorified 7.62x39mm that is accurate at longer range is..... I really can't believe we're even having this discussion. It is so far out of the realm of anything I'd even begin to consider a good idea.
My $.02.
Gee...which one is likely to be more effective at incapacitating an aggressive violent opponent?
http://www.tridentconcepts.com/alumni/Portals/0/NTForums_Attach/1823542651571.jpg
It appears to me that 75 grain TAP wins that competition hands down... Are you suggesting otherwise?
Well then you would be quite mistaken. You might wish to review the information here: https://www.m4carbine.net/showthread.php?t=22323.
In the above photos of bare gel test shots by three different calibers, all three projectiles offer adequate penetration depth, however the .308 155 gr AMAX is creating the most tissue damage, followed by the 6.8mm 115 gr OTM, then distantly trailed by the .223 75 gr OTM. One of the largest SWAT teams on the West Coast has used both the .223 Hornady 75 gr TAP and .308 155 gr Hornady AMAX for over a decade; the post-mortem forensic results of OIS incidents demonstrate substantially more tissue damage with the .308 AMAX projectiles compared to any .223 loads.
I am quite aware of the penetration capabilities of .223 projectiles through building materials; in fact, I believe we wrote the first papers discussing post intermediate barrier wounding effects back in the late 1980s at LAIR and early 1990's with the IWBA. Likewise, Dr. Fackler, the director of the LAIR wound ballistic laboratory, was the first individual to accurately describe the fragmentation effects of 5.56 mm projectiles in tissue back in the mid-1980's.
I am sorry you can't believe we are "having this discussion" and that it is "so far out of the realm of anything I'd even begin to consider a good idea"; I suggest you revisit the past 25 years of wound ballistic progress and try to envision that perhaps technology has improved and there are better options available now.
I'm curious at what point that the 762x39 became a poor combat cartridge myself.:blink:
The ONLY real selling point of the 5.56 AT THIS POINT is that it is cheap and ubiquitous. Every other feature of the round can be had in a better cartridge of some sort.
-you want frag? get a frangible or varmint round
-Barrier pen? copper or bonded
-AP? buy AP rounds
The 5.56 is a well proven and established round and we KNOW what it can and does do, but much like the AR-15 that made it famous... it's no longer the leading edge of the knife.
Well then you would be quite mistaken. You might wish to review the information here: https://www.m4carbine.net/showthread.php?t=22323.
In the above photos of bare gel test shots by three different calibers, all three projectiles offer adequate penetration depth, however the .308 155 gr AMAX is creating the most tissue damage, followed by the 6.8mm 115 gr OTM, then distantly trailed by the .223 75 gr OTM. One of the largest SWAT teams on the West Coast has used both the .223 Hornady 75 gr TAP and .308 155 gr Hornady AMAX for over a decade; the post-mortem forensic results of OIS incidents demonstrate substantially more tissue damage with the .308 AMAX projectiles compared to any .223 loads.
I am quite aware of the penetration capabilities of .223 projectiles through building materials; in fact, I believe we wrote the first papers discussing post intermediate barrier wounding effects back in the late 1980s at LAIR and early 1990's with the IWBA. Likewise, Dr. Fackler, the director of the LAIR wound ballistic laboratory, was the first individual to accurately describe the fragmentation effects of 5.56 mm projectiles in tissue back in the mid-1980's.
I am sorry you can't believe we are "having this discussion" and that it is "so far out of the realm of anything I'd even begin to consider a good idea"; I suggest you revisit the past 25 years of wound ballistic progress and try to envision that perhaps technology has improved and there are better options available now.
I'm not sure there is anything Dr. Fackler has written that I have not read at least twice.
The illustration provided there appears to be primarily comparing hydrostatic shock. From my reading of "Military Rifle Bullet Wound Patterns" by Dr. Fackler, I gathered that the hydrostatic shock is not all that reliable, and that fragmentation and the creation of multiple permanent cavities is more desirable.
While the sketches, as used by Dr. Fackler, are better at illustrating fragments than these pictures that show shredded gelatin more than anything... from what is visible here it appears that all three cartridges exhibit a similar "spread" of fragments. I'd consider 5.56mm to be superior since it does it more efficiently (the cartridge is lighter and smaller).
The past 25 years of terminal ballistics study, that I have been exposed to, leads me to the opposite conclusion.
And, before you say something, yes, I know who you are.
I'm curious at what point that the 762x39 became a poor combat cartridge myself.:blink:
The ONLY real selling point of the 5.56 AT THIS POINT is that it is cheap and ubiquitous. Every other feature of the round can be had in a better cartridge of some sort.
-you want frag? get a frangible or varmint round
-Barrier pen? copper or bonded
-AP? buy AP rounds
The 5.56 is a well proven and established round and we KNOW what it can and does do, but much like the AR-15 that made it famous... it's no longer the leading edge of the knife.
Not sure what you mean by saying that the AR15 is no longer the leading edge of the knife. I have yet to discover a better platform.
7.62x39mm became a poor combat cartridge when Dr. Fackler's research indicated it has the terminal performance of a pistol cartridge.... 7.62x39mm pretty much holds the title for worst intermediate rifle cartridge in widespread use today.
It sounds to me like you want a GPMG in 7.62NATO based on the criteria presented (aside from your suggestion we should get varmint projectiles to shoot people with)... why that leads you to believe 5.56NATO is not the best at its current job is illogical.
And, before you say something, yes, I know who you are.
Then you'd be well served to re-examine your desire to post here. You asked, he answered, and now you are still disagreeing with him. Worse still, you are doing so in a flippant manner, which I view as disrespectful.
This is a bad idea.
It is entirely possible to carry on this conversation with a far greater deference to knowledge, obviously outside your depth, being imparted.
Thanks.
Microalign
12-24-11, 18:33
7.62x39mm became a poor combat cartridge when Dr. Fackler's research indicated it has the terminal performance of a pistol cartridge.... 7.62x39mm pretty much holds the title for worst intermediate rifle cartridge in widespread use today.
Dr. Fackler proved that the 7.62x39 was a poor performer in the M43 FMJ format:
http://www.uthr.org/SpecialReports/Martin%20Fackler,%20Stockton%20case.txt
The great thing about the 10% gel test is that we can measure the performance of projectiles in a medium that very closely resembles the hydrolic content of human tissue. 7.62x39mm projectiles in the Hornday AMAX, or other well engineered expansion loads perform quite well in 10% gel tests. Thus, the 7.62x39 is a great cartridge when decent ammunition is used.
As the kind Doc states, there have been a whole host of improvements in weapons and ballistics. The last 10 years particularly have pushed us forward farther and faster than the previous 20 IMO. No currently used rifle is what it was ten years ago. There have been major steps in weapon/ballistic advances made after the ban expired and 9-11-2001.
Like it or not, the civilian world often leads the military in technology. weapon systems are no different especially now we are in the information age. It's basically like we operate in a huge testing lab where testing and results can be made available to anyone in a very short time. Doc Roberts has been and remains an important grounding element in ballistic research in what would otherwise be ruled by the guy with an attractive claim, a lot of spare time, a youtube video, and a high post count.
some earnest research on new platforms and available projectiles will reveal a great deal to one who seeks true knowledge.
if I havent said it recently... Thanks Doc for your, patient, candid and scientifically grounded responses to our questions.
jack
Then you'd be well served to re-examine your desire to post here. You asked, he answered, and now you are still disagreeing with him. Worse still, you are doing so in a flippant manner, which I view as disrespectful.
This is a bad idea.
It is entirely possible to carry on this conversation with a far greater deference to knowledge, obviously outside your depth, being imparted.
Thanks.
I'm not sure what you mean by disrespectful. I am merely not in agreement with Dr. Roberts... I wasn't aware that disagreement was not allowed.
If there is anything on this board I am qualified to comment on, it is terminal ballistics. While I have not had the time to amass the same credentials as Dr. Fackler or Dr. Roberts, for my age I think you will find I am very densely credentialed in the this field.
There are four people as far as the firearms/ammunition community goes that I would be absolutely honored to meet. Dr. Roberts is one of them. I have a habit, which some may say is a bad one, of being very plain and simply stating things as I see them.
I yield to Dr. Roberts' wisdom in this area. I am not in total agreement... but I will argue no further, and will examine the resources I have at my disposal again.
Thank you.
lamarbrog--of course well reasoned disagreement is allowed! How else can we learn from one another and advance knowledge. Please keep posting and inquiring--I'll do my best to provide additional information. More to follow.
Dr. Fackler proved that the 7.62x39 was a poor performer in the M43 FMJ format:
http://www.uthr.org/SpecialReports/Martin%20Fackler,%20Stockton%20case.txt
The great thing about the 10% gel test is that we can measure the performance of projectiles in a medium that very closely resembles the hydrolic content of human tissue. 7.62x39mm projectiles in the Hornday AMAX, or other well engineered expansion loads perform quite well in 10% gel tests. Thus, the 7.62x39 is a great cartridge when decent ammunition is used.
I have attended autopsies of murder victims where non-Russian 7.62X39 ammo was used, and particularly with the noted Hornady load the wounding is nothing like that of a pistol round.
Is there a confirmed verdict on the “temporal stretch” vs wound channel/fragment argument?
Thanks everyone for the great responses. Below is a comparison of the best performing barrier blind 5.56 round that I could find with the best performing 6.8 round that I could find from Doc's data on this site:
5.56 mm Fed 62 gr FBI TBBC JSP (XM556FBIT3):
BG: Pen = 16.5", NL = 1.5cm, Max TC 11.5 cm @ 9 cm pen/extending to 17 cm, RD = 0.46", RL = 0.32", RW = 56.6 gr
6.8 mm Hornady 110 gr VMAX PT:
BG: 13.8", NL=0.5cm, Max TC=15cm@12cm from 0.5-20cm; RD=0.54”, RL=0.22”, RW=55.5gr
Clearly, the RD of the 6.8 projectile is larger, as is the TC. The question, as always in life, is whether the benefits outweigh the cost.
When considering 5.56 OTM rounds that fail to upset beyond ~50 yards out of a SBR and fail to defeat common barriers, I feel that a stronger case can be made that the benefits of the 6.8 outweigh the cost.
If the most significant advantage of the best 6.8 rounds over the best 5.56 is 3.5 cm of additional TC and .09" additional RD, it is harder for me to justify the cost of an identical upper (probably $1500 after optics, muzzle devices, bcg, etc.) and practice ammo. (It is nearly $1 per round, and even if I primarily practice with 5.56 there is going to be some felt difference and I am going to want to shoot the 6.8 sometimes as well).
As Doc has mentioned in other threads, quality barrier blind rounds have performed well in OIS incidents. The FBI has also selected a barrier blind 5.56 round, whereas they adopted the .40 after having problems with smaller calibers. This tells me that these rounds will do their job, even if the 6.8 does offer a small advantage around the margins of shot placement.
Is there a confirmed verdict on the “temporal stretch” vs wound channel/fragment argument?
Temporary cavity wounds fluid filled and inelastic organs such as the heart, brain, liver, spleen, kidneys, spinal cord, etc. It has minimal effect on muscle, lung parenchyma, and elastic connective tissue such as blood vessels. Fragmenting rounds do have an advantage because the fragments can act synergistically with the temporary cavity to damage tissues not inherently prone to being damaged by temporary cavitation. The head, central thorax, and abdomen, however, are rich with highly vascular structures prone to being damaged by temporary cavitation. With fair shot placement, I would expect hostilities to cease regardless of whether or not the round fragments so long as it upsets early and creates TC.
Thanks everyone for the great responses. Below is a comparison of the best performing barrier blind 5.56 round that I could find with the best performing 6.8 round that I could find from Doc's data on this site:
5.56 mm Fed 62 gr FBI TBBC JSP (XM556FBIT3):
BG: Pen = 16.5", NL = 1.5cm, Max TC 11.5 cm @ 9 cm pen/extending to 17 cm, RD = 0.46", RL = 0.32", RW = 56.6 gr
6.8 mm Hornady 110 gr VMAX PT:
BG: 13.8", NL=0.5cm, Max TC=15cm@12cm from 0.5-20cm; RD=0.54”, RL=0.22”, RW=55.5gr
Clearly, the RD of the 6.8 projectile is larger, as is the TC. The question, as always in life, is whether the benefits outweigh the cost.
When considering 5.56 OTM rounds that fail to upset beyond ~50 yards out of a SBR and fail to defeat common barriers, I feel that a stronger case can be made that the benefits of the 6.8 outweigh the cost.
If the most significant advantage of the best 6.8 rounds over the best 5.56 is 3.5 cm of additional TC and .09" additional RD, it is harder for me to justify the cost of an identical upper (probably $1500 after optics, muzzle devices, bcg, etc.) and practice ammo. (It is nearly $1 per round, and even if I primarily practice with 5.56 there is going to be some felt difference and I am going to want to shoot the 6.8 sometimes as well).
As Doc has mentioned in other threads, quality barrier blind rounds have performed well in OIS incidents. The FBI has also selected a barrier blind 5.56 round, whereas they adopted the .40 after having problems with smaller calibers. This tells me that these rounds will do their job, even if the 6.8 does offer a small advantage around the margins of shot placement.
Temporary cavity wounds fluid filled and inelastic organs such as the heart, brain, liver, spleen, kidneys, spinal cord, etc. It has minimal effect on muscle, lung parenchyma, and elastic connective tissue such as blood vessels. Fragmenting rounds do have an advantage because the fragments can act synergistically with the temporary cavity to damage tissues not inherently prone to being damaged by temporary cavitation. The head, central thorax, and abdomen, however, are rich with highly vascular structures prone to being damaged by temporary cavitation. With fair shot placement, I would expect hostilities to cease regardless of whether or not the round fragments so long as it upsets early and creates TC.
Of those things you listed as being damaged by temporary cavitation, many are not of great importance for immediate survival. Destroying your opponent's liver is quite probably going to be fatal... but not immediately.
Suffocation through blood loss and damage to the central nervous system are the crucial factors here. CNS damage is largely just luck of the draw. If you get a spine shot, congratulations... I'm not counting on it, though.
That leaves suffocation through loss of blood. Since blood vessels are not readily damaged by temporary cavitation, maximum fragmentation is important because it allows a greater opportunity to strike a blood vessel.
Perhaps it would be easier for you to justify a switch to 6.8 if you looked at in a larger scope.
In your arsenal I'll bet you have various level and power ranges of weapons. Answer for yourself the following question:
"If I could find one caliber that could take the place of TWO that I currently use, would it be worth it to me?
Right now the paradigm is that we have four or more ranges that weapons cover:
-Handgun (9, 40, 45) 0-50
-Assault rifle (223, 762x39, 545x39) 0-300
-Battle rifle (308, 30-06) 50-600
-Sniper rifle (300, 338) 100-1500+
-Anti-materiel (50)
What would it be like to combine the Assault and Battle rifles categories into one system and caliber. you might lose a little on the upper end, but you'd gain on the lower end where most stuff happens anyway.
Two guys. One is a close freind and the other just some guy on the internet. Internet guy shoots hogs for a living. tests out calibers and loads on REAL FLESH all the time. Claims that the 6.8 made a SIGNIFICANT difference over 223 regardless of bullet used, in how well the AR killed hogs. has HUNDREDS of kills a year. A LOT of hunters are discovering that the 6.8 has a lot of merit and it's gaining a lot of popularity in that circle.
Other friend has several human kills under his belt using good ol M16a2's and M855. Claims he never had any issues with the bullet or their ability to kill, and TO THIS DAY stands by the system and the bullets available with most of his "war" being the M855. Has NO INTENTION of switching to anything different either. And thats from a guy who tries out and learns new stuff all the time!
Heres the rub. Both are correct and have excellent reasons for using what they do. IMO it's always gonna be the shooter first over the ballistics. in fact the ballistics pretty much come LAST in the progression of things you need when killing stuff.
If I were starting from scratch and buying a new platform and any caliber I wanted, then maybe I'd go with one of the super new gen carbines and the 6.8 instead of two whole guns and two calibers. I mean, if you are gonna learn something why not start out with something new right? problem is, most folks are not in that boat, so the decision is much more difficult and getting rid of the 223 and 308 is just not an option for them.
the 6.8 has a lot to offer, but only YOU will be able to determine whether it's "worth it"
Perhaps it would be easier for you to justify a switch to 6.8 if you looked at in a larger scope.
In your arsenal I'll bet you have various level and power ranges of weapons. Answer for yourself the following question:
"If I could find one caliber that could take the place of TWO that I currently use, would it be worth it to me?
Right now the paradigm is that we have four or more ranges that weapons cover:
-Handgun (9, 40, 45) 0-50
-Assault rifle (223, 762x39, 545x39) 0-300
-Battle rifle (308, 30-06) 50-600
-Sniper rifle (300, 338) 100-1500+
-Anti-materiel (50)
What would it be like to combine the Assault and Battle rifles categories into one system and caliber. you might lose a little on the upper end, but you'd gain on the lower end where most stuff happens anyway.
Two guys. One is a close freind and the other just some guy on the internet. Internet guy shoots hogs for a living. tests out calibers and loads on REAL FLESH all the time. Claims that the 6.8 made a SIGNIFICANT difference over 223 regardless of bullet used, in how well the AR killed hogs. has HUNDREDS of kills a year. A LOT of hunters are discovering that the 6.8 has a lot of merit and it's gaining a lot of popularity in that circle.
Other friend has several human kills under his belt using good ol M16a2's and M855. Claims he never had any issues with the bullet or their ability to kill, and TO THIS DAY stands by the system and the bullets available with most of his "war" being the M855. Has NO INTENTION of switching to anything different either. And thats from a guy who tries out and learns new stuff all the time!
Heres the rub. Both are correct and have excellent reasons for using what they do. IMO it's always gonna be the shooter first over the ballistics. in fact the ballistics pretty much come LAST in the progression of things you need when killing stuff.
If I were starting from scratch and buying a new platform and any caliber I wanted, then maybe I'd go with one of the super new gen carbines and the 6.8 instead of two whole guns and two calibers. I mean, if you are gonna learn something why not start out with something new right? problem is, most folks are not in that boat, so the decision is much more difficult and getting rid of the 223 and 308 is just not an option for them.
the 6.8 has a lot to offer, but only YOU will be able to determine whether it's "worth it"
I agree with you just about right down the line. If I was starting fresh and practice ammo was reasonably priced, I think the 6.8 would be a more logical choice than 5.56. Given what most of us already have invested in 5.56 carbines coupled with the price of magazines and practice ammo in 6.8, it does not seem worth it to me at this point. Before I became aware of barrier blind 5.56 rounds that worked well out to 300 yards, the gap seemed larger and the 6.8 looked a lot more attractive.
I have heard the same thing from hunters, but keep in mind bipedal thin-skinned human have a lot less in the way of vitals than hogs. If I was going hog hunting, a 6.8 upper would once again be high on my list.
Everyone I know who has used the 5.56 in combat tells me it works fine as well.
Of those things you listed as being damaged by temporary cavitation, many are not of great importance for immediate survival. Destroying your opponent's liver is quite probably going to be fatal... but not immediately.
Suffocation through blood loss and damage to the central nervous system are the crucial factors here. CNS damage is largely just luck of the draw. If you get a spine shot, congratulations... I'm not counting on it, though.
That leaves suffocation through loss of blood. Since blood vessels are not readily damaged by temporary cavitation, maximum fragmentation is important because it allows a greater opportunity to strike a blood vessel.
The liver, spleen, kidneys, etc. are vascular organs that accept a high percentage of cardiac output relative to their mass. I have seen plenty of blunt liver trauma (which is analogous to the injury caused by TC) and it can be disastrous. A temporary cavity tearing through the liver would cause rapid hemorrhage and incapacitation; it is definitely not an organ you want injured.
vicious_cb
12-26-11, 00:41
Perhaps it would be easier for you to justify a switch to 6.8 if you looked at in a larger scope.
In your arsenal I'll bet you have various level and power ranges of weapons. Answer for yourself the following question:
"If I could find one caliber that could take the place of TWO that I currently use, would it be worth it to me?
Right now the paradigm is that we have four or more ranges that weapons cover:
-Handgun (9, 40, 45) 0-50
-Assault rifle (223, 762x39, 545x39) 0-300
-Battle rifle (308, 30-06) 50-600
-Sniper rifle (300, 338) 100-1500+
-Anti-materiel (50)
What would it be like to combine the Assault and Battle rifles categories into one system and caliber. you might lose a little on the upper end, but you'd gain on the lower end where most stuff happens anyway.
Things aren't as cut and dry as that, not to mention its the skill of the shooter that will determine the effective range of a weapon/caliber system. I bet there are guys here or know of guys who have slain past 600m with 5.56. As for replacing 2 calibers, if you look at the BCs of 6.8 match loads, they aren't much better than 5.56 match loads.
Things aren't as cut and dry as that, not to mention its the skill of the shooter that will determine the effective range of a weapon/caliber system. I bet there are guys here or know of guys who have slain past 600m with 5.56. As for replacing 2 calibers, if you look at the BCs of 6.8 match loads, they aren't much better than 5.56 match loads.
you should read the rest of my post where I say as much.
That handy "rule" is packaged for easy consumption. Hell, even math has exceptions to rules.
Things aren't as cut and dry as that, not to mention its the skill of the shooter that will determine the effective range of a weapon/caliber system. I bet there are guys here or know of guys who have slain past 600m with 5.56. As for replacing 2 calibers, if you look at the BCs of 6.8 match loads, they aren't much better than 5.56 match loads.
I think the point you guys are missing is that for those match loads you speak of, the cost of the ammo is the same. Actually, when comparing the 5.56 Black Hills 50gr TSX, the Hornady 6.8 110 BTHP is significantly less money. Doc can comment on which is the better performing round. This influenced me to go ahead and invest in the price of admission for 6.8. When training, I find the difference in recoil in the AR platform a non-issue on accuracy and so the cheap 5.56 ammo is a viable alternative for use as a practice round. The XM193 actually has more recoil than alot of the other rounds I have shot including the weaker 75gr TAP FPD. Unless you are training monthly (I wish) for your job or you have unlimited time and cash, swapping optics and light mounts from the 5.56 to 6.8 is a non-issue, so you really should just be considering the cost of the upper and mags.
I really enjoy my MSAR E4 for this reason. I purchased a 6.8 kit from Ratworx and all that is required is a bolt and EASY barrel swap (AUG platform). Optics and light stays in place. With a few clicks on the Trijicon and I'm gtg.
I think the main problem is that a while back ("while back" as used in man-terms, like "The other day...") the military was ONLY fielding FMJ ammunition, and the only other ammunition available in .223 was of the varmint variety, or fragmenting JSP's (JSP's that "failed", etc.)
The 7.62x39 was only readily available in FMJ.
6mm, 7mm, .308, .30-06 etc. were only available in heavier rifles, or rifles like the HK-91, etc. They didn't see a whole ton of use in killing people except in FMJ. Everyone agreed that .30-06 in FMJ > 5.56 FMJ. However, the neighbor family 10 houses down that you like hanging out with would ALSO agree that your M1A>AR-15...
Well, now things are different. Ammunition performance has been tuned in such a way that construction and material allow the penetration to be controlled through either expansion, fragmentation, or both.
Now, mass and kinetic energy are king, because bullet construction takes care of over-penetration and terminal performance.
The crux of the matter has become...Can I accurately control a light weapon shooting projectiles of this weight rapidly? and then picking the platform that launches the biggest projectile with the highest KE that you can rapidly and effectively shoot that is available in the platform of your choosing/has the features you need to run it effectively.
Then you select a projectile that has maximum upset and penetrates between 12-16".
The 5.56 is very controllable, but not much is given up by going to 6.8, etc.
Summation:
It's no-longer a question of cartridge characteristic. It's a question of platform characteristic, because it has become about maximum mass and KE vs. controllability while the projectile manufacturers have taken care of the rest by giving us projectiles tuned to the task across the caliber and velocity spectrum.
Just my take on it.
I agree with you just about right down the line. If I was starting fresh and practice ammo was reasonably priced, I think the 6.8 would be a more logical choice than 5.56. Given what most of us already have invested in 5.56 carbines coupled with the price of magazines and practice ammo in 6.8, it does not seem worth it to me at this point. Before I became aware of barrier blind 5.56 rounds that worked well out to 300 yards, the gap seemed larger and the 6.8 looked a lot more attractive.
I have heard the same thing from hunters, but keep in mind bipedal thin-skinned human have a lot less in the way of vitals than hogs. If I was going hog hunting, a 6.8 upper would once again be high on my list.
Everyone I know who has used the 5.56 in combat tells me it works fine as well.
As another data-point, I have heard the same. My former roommate used the 5.56 in the guise of M855 to kill people. We didn't discuss it in detail as he's not someone who glorifies what he did or wishes to reminisce about killing people, but he simply said "If you put it COM where it belongs, it did it's job quickly and decisively. I only used it out to about 120 yards or so. Most of our combat was closer in."
He was in Iraq for a few years back in the early 2000's.
Then you'd be well served to re-examine your desire to post here. You asked, he answered, and now you are still disagreeing with him. Worse still, you are doing so in a flippant manner, which I view as disrespectful.
This is a bad idea.
It is entirely possible to carry on this conversation with a far greater deference to knowledge, obviously outside your depth, being imparted.
Thanks.
lamarbrog--of course well reasoned disagreement is allowed! How else can we learn from one another and advance knowledge. Please keep posting and inquiring--I'll do my best to provide additional information. More to follow.
+1. I have disagreed with you on several occasions. I have a medical degree, but am not an MD, nor have I seen anyone shot personally besides a friend who was cleaning his G32, but that's another story. Dr. Roberts politely and professionally has disagreed with me, supported his stance, and changed my opinion on a number of things after I saw his side of the story. I never once found him to be "above" polite debate with me, nor did he ever "talk down" to me from his educational or professional position. If people DO NOT post their disagreement with him, they are missing out. I learned more from people by disagreeing with them than agreeing. The "trick" is to remain open-minded to THEIR side of the debate, engage respectfully, and focus on LEARNING more than "WINNING".
I have found Dr. Roberts to be one of the most "accessible" and polite MD's I have spoken to. That includes the ones I work with. He is a valuable asset to the community, and I don't say this to suck up, I say this because you don't HAVE TO suck up to the guy, and you CAN get cross-wise with him a full 90* on a topic and as long as you are polite, he will engage you intelligently on the issue and you have a wonderful opportunity to learn things. I cannot recall a single time where he has said anything analogous to "Because I said so, and here is my resume". No. He point-by-point explains things in layman's terms, or as technically detailed as you would like. Or directs you to where it has been done 1,000 times over if you ask something ridiculous.
Lets not relegate him to an ivory tower or canonize his words. The guy is a great teacher and it would seriously hamper our ability to learn anything from him. If someone still truly disagrees after Dr. Roberts has said his piece on the matter, why begrudge them that? As long as Dr. Roberts is responding, he has something to say. He doesn't need "protection" from the questions of others.
I do fully agree that he deserves the same respect that others deserve--to be engaged politely and respectfully, as he has done so with those who engage him.
I have found that to be true of any MD I have spoken to. I call and wake MD's up all night long at work, and have yet to be lambasted or treated ill for it. I simply speak respectfully, and accept nothing short in return. It has worked well.
Lets not relegate him to an ivory tower or canonize his words. The guy is a great teacher and it would seriously hamper our ability to learn anything from him. If someone still truly disagrees after Dr. Roberts has said his piece on the matter, why begrudge them that? As long as MD Roberts is responding, he has something to say. He doesn't need "protection" from the questions of others.
It was not the question from which he was being "protected". Just remember that not everyone's perspective is the same during their participation on this forum. Staff and Mods see things a little differently, based on our roles for site participation.
The words written indicated that lamarbrog obviously considered himself a peer of Dr. Roberts, and then closed his disagreement with "And, before you say something, yes, I know who you are."
This sounded flippant, and dismissive. Which might work Ok for others, except that his comment was directed towards a respected Industry Professional. Until further clarification was made, this is a no-go on this site.
Now that I have clarification, and Doc has voiced his consent to furthering the discussion, it appears benign. At the time, it looked like it was going to be an issue that needed handling.
Again, this is about perspective, mods and staff are required to look towards maintaining some semblance of order, and that looked like a sure derailment in the making.
I do fully agree that he deserves the same respect that others deserve--to be engaged politely and respectfully, as he has done so with those who engage him.
Actually, his work, and his identification as an IP, afford him an elevated level of respect. We're not trying to fool ourselves on M4Carbine into believing that all opinions are equal, they're not.
You are 100% correct though, his IP status and work does not set him above rational, and respectful, disagreement. I just wasn't sure that was the road on which lamarbrog was headed.
Thanks for taking the time to respond, but it would appear this particular issue has been ironed out, and we can return to our regularly scheduled programming. :D
It was not the question from which he was being "protected". Just remember that not everyone's perspective is the same during their participation on this forum. Staff and Mods see things a little differently, based on our roles for site participation.
The words written indicated that lamarbrog obviously considered himself a peer of Dr. Roberts, and then closed his disagreement with "And, before you say something, yes, I know who you are."
This sounded flippant, and dismissive. Which might work Ok for others, except that his comment was directed towards a respected Industry Professional. Until further clarification was made, this is a no-go on this site.
Now that I have clarification, and Doc has voiced his consent to furthering the discussion, it appears benign. At the time, it looked like it was going to be an issue that needed handling.
Again, this is about perspective, mods and staff are required to look towards maintaining some semblance of order, and that looked like a sure derailment in the making.
Understood. I took his comment to mean "I know who you are, I know you know a lot of things, I still disagree with you, regardless, and require clarification if I am to change my opinion."
However, you look at things differently because it's your "job", and I understand that. Just like as a shopper, I wonder if someone has something dangerous to me in their heavy coat in the summer in wal-mart. The store manager is worried about his electronics displays, and the coat-wearer feels alienated because their chemo treatments leave them easily chilled and everyone is looking at them funny.
Actually, his work, and his identification as an IP, afford him an elevated level of respect. We're not trying to fool ourselves on M4Carbine into believing that all opinions are equal, they're not.
His position deserves more respect because there is more knowledge and experience behind it, and his opinion should carry more weight because of that, but I feel that every human being who does their job, supports society, and respects others deserves to be treated as we ourselves want to be treated. Black, white, rich, poor, MD, GED.
You are 100% correct though, his IP status and work does not set him above rational, and respectful, disagreement. I just wasn't sure that was the road on which lamarbrog was headed.
Thanks for taking the time to respond, but it would appear this particular issue has been ironed out, and we can return to our regularly scheduled programming. :D
Agreed. I have just seen so many times where an "industry professional" is placed on a pedestal as "beyond question" and it irks me. I am happy to see that Dr. Roberts is not of that ilk.
I am interested in what appears to be a "change mid-stream" as to Dr. Roberts views on 5.56 ammunition. I understand that it is due to new technology in projectile design being applied. However, it is interesting to me that he has changed his stance after preaching "Heavy OTM except through glass" for so long. It's refreshing to see someone "important" change their tune to support new data without fearing that it will erode their status.
People rarely use the sea-green.
Of those things you listed as being damaged by temporary cavitation, many are not of great importance for immediate survival. Destroying your opponent's liver is quite probably going to be fatal... but not immediately.
Suffocation through blood loss and damage to the central nervous system are the crucial factors here. CNS damage is largely just luck of the draw. If you get a spine shot, congratulations... I'm not counting on it, though.
That leaves suffocation through loss of blood. Since blood vessels are not readily damaged by temporary cavitation, maximum fragmentation is important because it allows a greater opportunity to strike a blood vessel.
With all due respect, suffocation (asphyxiation) is not an incapacitation mechanism from a gun shot wound.
The major complication from massive blood loss is hypovolemic shock, resulting in inadequate peripheral perfusion of the tissues, which eventually causes circulatory collapse due to major organ failure throughout the body, resulting in death.
It the liver, spleen and kidneys are damaged, the likelihood of additional damage is present, and will contribute to reducing the effects of the bodies cardiovascular responses to the trauma sustained.
With all due respect, suffocation (asphyxiation) is not an incapacitation mechanism from a gun shot wound.
The major complication from massive blood loss is hypovolemic shock, resulting in inadequate peripheral perfusion of the tissues, which eventually causes circulatory collapse due to major organ failure throughout the body, resulting in death.
It the liver, spleen and kidneys are damaged, the likelihood of additional damage is present, and will contribute to reducing the effects of the bodies cardiovascular responses to the trauma sustained.
My apologies. I was somewhat distracted when I wrote that. I was going for "exsanguination", but instead went with the colloquial form of "asphyxiation". Anyway, blood loss.
As you say, I'm not quite sure how someone would suffocate as a result of a gunshot wound.
In response to the OP's question - "is there much of a point to larger calibers such as the 6.8 anymore?"
Yes.
Wounding comes from penetration, permanent cavity, temporary cavity, and fragmentation right? Right. So the bigger the bullet, the more mass, more diameter, more expansion or more fragmentation you're going to achieve. Unlike the small differences between 9mm, 40sw & 45acp wounding capabilities, the differences between rifle wound tracks are quite significant as you can see from Doc's posted pics. Anything a 5.56mm can do, a 6.8mm or 7.62mm can do better and the difference is not marginal. Scaling up a load from 5.56mm to a 6.8mm or 7.62mm means that you'll get a lot more fragmentation or controlled expansion, along with a lot more temporary cavity. No matter what you're shooting from dogs, hogs, people or large game, the larger bullet of similar design is always going to have a larger and more horrendous wound track.
In response to the OP's question - "is there much of a point to larger calibers such as the 6.8 anymore?"
Yes.
Wounding comes from penetration, permanent cavity, temporary cavity, and fragmentation right? Right. So the bigger the bullet, the more mass, more diameter, more expansion or more fragmentation you're going to achieve. Unlike the small differences between 9mm, 40sw & 45acp wounding capabilities, the differences between rifle wound tracks are quite significant as you can see from Doc's posted pics. Anything a 5.56mm can do, a 6.8mm or 7.62mm can do better and the difference is not marginal. Scaling up a load from 5.56mm to a 6.8mm or 7.62mm means that you'll get a lot more fragmentation or controlled expansion, along with a lot more temporary cavity. No matter what you're shooting from dogs, hogs, people or large game, the larger bullet of similar design is always going to have a larger and more horrendous wound track.
100% agree with this, however, with the larger rounds, comes greater penetration, correct?
If a rifle is being used in an HD or apartment defense type role where there are people behind just a couple pieces of sheetrock, I would think that excessive penetration also has to be factored in. I realize that any round worth using for defensive purposes is going to penetrate sheetrock with ease, but I would still like to minimize that as much as possible.
Something along the lines of "given identical bullet constructions" has been mentioned several times.
The problem is when scaling up from 5.56 to 6.8 to 7.62, the construction needs to be adjusted to retain similar performance and there are limits to how much adjustments can be made.
This is mostly related to bullet energy per weight.
The 5.56 (at 55-75 grains) TENDS to be over energized, fragmenting at close ranges at the expense of penetration.
The 7.62x51 (at 130-175 grains) TENDS to be under energized, penetrating excessively at the expense of expansion.
The 6.8x43 ( at 90-120 grains) TENDS to have optimal energies to allow the projectiles to expand and penetrate consistently.
Again, advanced (expensive) bullet constructions like monolithic copper alloys and thick jacket bonded core can counteract these tendencies and produce excellent terminal effects.
The intermediate weight projectiles can produce excellent terminal effects even with standard constructions.
No. Penetration can be exactly the same, just like with duty handgun rounds of different calibers. Assuming it is engineered to do so, a larger diameter projectile just damages a wider swath of tissue, but does not go any deeper than the design requirements--typically 12-18".
As shown earlier in this thread, note that all three calibers penetrate to the same depth, but as the bullets get larger, much more tissue will be destroyed:
http://www.tridentconcepts.com/alumni/Portals/0/NTForums_Attach/1823542651571.jpg
Leatherneck556
12-29-11, 07:28
WS6 started to hint at what I see as the "real" issue here when he mentioned this being a matter of platform.
I cannot debate that the bigger calibers have better terminal effects. I don't think anyone can make a well-reasoned, scientifically-backed argument to the contrary.
So with that in mind, and all other things being equal, I'd rather hit my target with the bigger bullet.
But it's key to note that all other things are not equal. So the questions of platform, cost, availability, intended use, weight, recoil, etc come into play.
Would I prefer to have an LMT MWS with an ACOG TA11 and magazines full of 150gr Scirocco bonded over a 16" barreled AR15 with an ACOG TA33 and Mk318 for my "end of the world" rifle? Answering purely from a perspective of ballistics (both terminal and external), yes I would.
But answering from a perspective of platform characteristics such as lighter weight ammunition (can carry more of it), larger magazine capacity (more shots before reloading), lower recoil (can fire faster while maintaining accuracy), lighter weight/smaller size of weapon (can use it better and maneuver the weapon faster in close range), cost (can stock up on more of my "premium" ammo, and can afford to train more), availability of parts and ammo when scavenging (5.56 AR's are probably a lot more prolific in the US than .308 AR's), and universality and availability of reliable magazines, I would prefer the 5.56 gun.
So I think the question here isn't about whether the bigger rounds are still relevant - they certainly are. The real questions - in my opinion - should be:
1. What is the smallest round that I can use while still retaining adequate terminal effectiveness?
2. What is the largest round/platform that I can reasonably and effectively employ (and/or afford to purchase)?
3. What balance between the two do I personally want to draw?
Those last two questions are entirely matters of individual preference, but the answer to the first one can be given to us by researchers like Doc.
So that would be my question to Doc: It's clear that the 6.8 and .308 provide significantly improved terminal ballistics over the 5.56, but are barrier blind 5.56 rounds still up to the task of "general purpose" rifle use? Do they penetrate barriers well enough, have adequate terminal effectiveness out to 300m, and can a shooter use them to accurately engage man-sized targets out to 600m? (I know that I can do this last one with Mk318 in an 16" middy despite assault rifles and intermediate calibers being "designed" for 300m and less). I'm not asking if they are the best suited for the task - obviously they are not. But are they able to adequately handle the task? In other words, barrier blind 6.8 and .308 rounds are better than barrier blind 5.56 rounds, but does that mean that the 5.56 rounds are suddenly not good enough anymore?
What perceptible differences are there in terminal effectiveness on a living target between large rounds and small rounds? Do they put the target down more quickly with fewer shots? Do they make up for bad shot placement, putting down targets reliably even with periphery hits? Most importantly - will I as the shooter ever be able to actually perceive the difference if I shoot a human adversary with the aforementioned rounds? There is a quantifiable difference in ballistic gelatin "wound" profiles which means the bigger rounds will cause more damage in a human target, which means that you will theoretically see faster/more reliable incapacitation. Is that actually the case, or do the smaller 5.56 rounds do enough damage to begin with, and the larger rounds' enhanced wounding capability is wasted/unnecessary/overkill? I've been in firefights where I was armed with a 5.56 carbine, but I've never personally shot anybody or seen anybody shot.
Obviously there are rounds that are too small. You can stop an attacker with 5.7, 4.6, or .22lr, but they do so little damage and take so many shots to work reliably that no informed person would select them over other calibers such as 9mm, 5.56, or .308. In this sense, those rounds are inadequate or "too small". Is that the case with 5.56 as it relates to 6.8/.308, or is 5.56 good enough for general purpose use?
That, I think, is the real question. And I'm sincerely eager to hear the answer.
Just because 6.8 & 7.62 both can do a job better than 5.56, that doesn't mean that 5.56 is obsolete or shouldn't be used. I think it's proved itself very well at being a immediate incapacitator and no, there is no substitute for shot placement.
This thread was originally about whether the larger calibers were relevant anymore, funny how it's got turned around to be if the 5.56 relevant anymore...
:laugh:
Microalign
12-29-11, 12:25
No. Penetration can be exactly the same, just like with duty handgun rounds of different calibers. Assuming it is engineered to do so, a larger diameter projectile just damages a wider swath of tissue, but does not go any deeper than the design requirements--typically 12-18".
As shown earlier in this thread, note that all three calibers penetrate to the same depth, but as the bullets get larger, much more tissue will be destroyed:
http://www.tridentconcepts.com/alumni/Portals/0/NTForums_Attach/1823542651571.jpg
I'm not sure how anyone can argue with the data that larger rifle calibers produce better terminal effects, particularly at longer ranges. Many people make the 5.56 work for them because of the sear volume of logistics advantages that come with it. The 6.8 SPC is impractical for carbine use unless you have an agency that supplies you with lots of ammo, or you reload. However, if the 6.8 SPC were much closer to the 5.56 in training costs, magazine variety, platform variety, and duty ammo variety I think that many more people would choose the 6.8 over the 5.56. I would if my agency allowed me to use 6.8. However, since my agency limits me to the 5.56, and that I can pick up all the 5.56 brass off my agency range that I need, it makes far more sense to stick with 5.56.
We need to start seeing 300 BLK added to the mix.
We need to start seeing 300 BLK added to the mix.
I'm no expert but modern expanding ammo like the Corbon DPX loading used in the 7.62x39 has been described as marginally better than similar loading in 5.56
It would be nice to have something more definitive than the already accepted logic that the .308 is better than 6.8 which is better than 5.56. Maybe trying to find that illusive optimized setup when people and the situations surrounding a shooting are so varied is why the descriptions remain so vague.
No. Penetration can be exactly the same, just like with duty handgun rounds of different calibers. Assuming it is engineered to do so, a larger diameter projectile just damages a wider swath of tissue, but does not go any deeper than the design requirements--typically 12-18".
As shown earlier in this thread, note that all three calibers penetrate to the same depth, but as the bullets get larger, much more tissue will be destroyed:
I agree 100% IF penetration is in the ideal range.
But typical penetrations are not equal between calibers/weights.
The 155 AMAX seems to be an exception with the .308.
The average and median .308 penetration from the ATK LE Data Book (http://le.atk.com/pdf/223RifleDataBook.pdf) is 19.5" in bare gel.
This exceeds the ideal range and leaves performance on the table.
Along with this comes initial neck lengths typically in 1-3" range.
Only 2 out of 5 308 loads meet the 12-18" criteria, with the rest over penetrating.
Only 3 out of 7 223/556 loads meet the 12-18" criteria, with two under penetrating and two over penetrating.
From Hornady LE (http://www.hornadyle.com/products/detail6548.html?id=72&sID=151) and SSA (http://www.ssarmory.com/images/SSA6.8SPC_85gr_BarnesTSX.pdf), 4 out of 4 6.8 loads meet the 12-18" criteria. Those are the AMAX, VMAX, BTHP and 85TSX.
All have initial neck lengths under 1".
The 7.62x39 123 VMAX shows similar excellent performance.
Either engineers have done a better job optimizing performance in the middle weight bullets, or it is naturally easier to achieve it.
Either engineers have done a better job optimizing performance in the middle weight bullets, or it is naturally easier to achieve it.
Regarding Clint's statement and the notion above that bigger diameter is better, this raised some questions for me about the development of 6.8. The story seemed to indicate the developers of the cartridge tested bullet diameters from 5.56 up to 7.62. The results of their findings (according to the internet and we know everything on the internet is true) was that the 7mm had the most devastating terminal performance, even over the 7.62. They also stated that the 6.5 was the most accurrate. The 6.8 was decided on because it gave up very little in terminal effectiveness to the 7mm and was almost as accurrate as the 6.5. I am assuming that all this was within the parameters of using a cartridge OAL that did not exceed that of the AR-15 platform and the velocities that resulted from this limitation. This would fit with some of the statements above regarding optimal velocity range for specific calibers, but what about the 6.5 made it inherrently more accurrate than the 7mm or 7.62? Was it BC alone and due to the geometry that was settled on using the Remmington parent case? Was velocity alone (or the lack thereof) responsible for the fact the 7mm outperformed the 7.62 in testing? What ramifications does this have for the 300blk given the fact it uses a 7.62mm projectile but is limited in velocity due to the constraints of the 5.56 parent cartridge? I am assuming that only range would be affected.
Leatherneck556
12-30-11, 06:37
Just because 6.8 & 7.62 both can do a job better than 5.56, that doesn't mean that 5.56 is obsolete or shouldn't be used. I think it's proved itself very well at being a immediate incapacitator and no, there is no substitute for shot placement.
This thread was originally about whether the larger calibers were relevant anymore, funny how it's got turned around to be if the 5.56 relevant anymore...
:laugh:
My sentiments exactly. When I posted the above monstrosity, I was sincerely asking those questions, but I also had an eye toward the notion that 5.56 is perfectly adequate.
I'm a 5.56 (AR) and 7.62x39 (AK) guy right now. I would kind of like to step up to a bigger AR platform, but it's hard to justify the cost. I've got a couple awesome 5.56 guns, dozens of magazines for them, and a few hundred rounds of good bonded 5.56 JSP. On top of that, the training ammo is cheap and plentiful and I'm currently trying to get hired by an agency that allows its officers to purchase their own 5.56/.223 patrol rifles.
I don't think that anything Doc has ever said indicates that the .308 and 6.8 offerings are just so much better than the 5.56 loads that 5.56 isn't even worth messing around with anymore, but it's easy to get caught up in the pictures and the dramatic differences displayed in gel testing and then subconsciously draw that conclusion. Buying an LMT MWS for "general purpose" use is something I want to do, but the rifle itself costs a lot of money. Then I'm also going to pick up magazines, optics, and ammo. All told, I might end up spending $4000 just to get set up with a rifle, accessories, and a thousand or so rounds of practice ammo. I really feel like I'd be better off if I spent that same $4000 on practice ammo, classes, and enhanced barrier blind rounds for my current weapons.
This is the most important thing to remember, I think. It's the same thing Doc said about preferring to go into combat with a guy that has an M16A1 and M193 who shoots 15,000 rounds per year than a guy with the newest whiz-bang rifle and bullet but only shoots 500 rounds per year.
I get where you coming from. I have spent over $1300 alone just on 6.8 mags.
I don't think that anything Doc has ever said indicates that the .308 and 6.8 offerings are just so much better than the 5.56 loads that 5.56 isn't even worth messing around with anymore
Close...
Intermediate calibers (6.5-7mm) with well designed barrier blind loads are substantially MORE impressive than any 5.56 mm load...
Worth it is a more involved discussion.
5.56 still has a place for a variety of reasons, but I think its fair to say 556 is NOT the pinnacle of small arms performance.
Leatherneck556
12-30-11, 15:37
5.56 still has a place for a variety of reasons, but I think its fair to say 556 is NOT the pinnacle of small arms performance.
Exactly. The other rounds exhibit substantially better terminal performance, but 5.56 certainly isn't now useless.
FWIW, for a variety of reasons I still use a 5.56 mm AR15...
http://farm7.static.flickr.com/6050/6338342552_13b7fb84da_z.jpg
umm...
did everyone just agree on something here?
We need to start seeing 300 BLK added to the mix.
http://img577.imageshack.us/img577/7161/300aacblkbarriersummary.jpg
That looks like some excellent and consistent performance.
Leatherneck556
12-31-11, 00:56
umm...
did everyone just agree on something here?
http://cdn.pimpmyspace.org/media/pms/c/1b/xa/tk/bestfranz.gif
Doc, I was wondering if you could please comment on my questions above regarding the development of the 6.8 cartridge since you are intimately familiar with the round.
Ok, I thought 5.56 was better all around since the 6.8 was maxed out at 4-500 yds, while the 5.56 can be stretched to 6-700yds. Wouldnt the 6.5 have better potential since it can offer similar performance as the 6.8 close in and reach out past 1000yds?
Is the 6.5 just stunted because of the company or is there an engineering flaw with the round?
IMO 5.56 is the best combo of terminal ballistics, price(especially for training), availability, rounds/mag, and wieght. Ill be sticking with it for a LONG time. That said, i doubt im good enough to notice a difference at this point.
http://img577.imageshack.us/img577/7161/300aacblkbarriersummary.jpg
That looks like some excellent and consistent performance.
The penetration looks a little on the excessive side though, doesn't it? Being that 12-18" is considered ideal.
Microalign
12-31-11, 16:10
Ok, I thought 5.56 was better all around since the 6.8 was maxed out at 4-500 yds, while the 5.56 can be stretched to 6-700yds. Wouldnt the 6.5 have better potential since it can offer similar performance as the 6.8 close in and reach out past 1000yds?
Why not just use the .308 if you want longer ranged performance? The .308 is a MUCH more capable long range system with bullet weights all the way up to 220gr if that is what you need. Many .308 loads are superior to the 6.5 in terms of ballistic coefficents, it has much better terminal effects(better for hunting large game), much better barrier penetration, ammo variety is much better, training ammo is cheaper, it has better magazines,........etc, etc, the advantages go on and on. Rifles like the LaRue PredAR and SCAR 17 are almost as light as many 5.56 rifles, and they are very user friendly.
Ok, I thought 5.56 was better all around since the 6.8 was maxed out at 4-500 yds, while the 5.56 can be stretched to 6-700yds.
I think you have this backwards. The maximum fragmentation range for most 5.56 rounds is under 300 yards when fired from a 14.5 or 16 inch barrel. The development of the 6.8 was to increase the performance out to 500 yards when fired from an M4. I don't know of any 5.56 round that is effective at 600 yards and even when the Army listed the effective range as 470 yards, this was based on a 20 inche barrel and really wishful thinking IMO.
vicious_cb
12-31-11, 20:37
I think you have this backwards. The maximum fragmentation range for most 5.56 rounds is under 300 yards when fired from a 14.5 or 16 inch barrel. The development of the 6.8 was to increase the performance out to 500 yards when fired from an M4. I don't know of any 5.56 round that is effective at 600 yards and even when the Army listed the effective range as 470 yards, this was based on a 20 inche barrel and really wishful thinking IMO.
Again, what do you mean by effective range? The proper definition of effective range has nothing to do with terminal performance but rather the ability to get hits on target above a certain percentage under field conditions. This is why you have effective range on point and area targets. 5.56 will still be deadly past 1000 yards even long after if falls to sub sonic speed.
Again, what do you mean by effective range? The proper definition of effective range has nothing to do with terminal performance but rather the ability to get hits on target above a certain percentage under field conditions. This is why you have effective range on point and area targets. 5.56 will still be deadly past 1000 yards even long after if falls to sub sonic speed.
Maybe in Call of Duty: Modern Warfare but not in the real world. Nevermind the fact that the 5.56 bullet wouldn't have enough velocity at 1000 yards to frag or cause much more than a .22 caliber wound track with very little stretch cavity, but even an EXPERT Marine Sniper would have a VERY difficult time getting the 5.56 on a man sized target at a 1000 yards. A Hornady 75 gr BTHP match bullet (BC .395) with a generous muzzle velocity of 2700fps will have dropped 455 inches at 1000 yards and even the slightest wind will blow it severely off course at anything over 500 yards.
By the way, the Army means "effective" in that it will neutralize a human target at that range.
The penetration looks a little on the excessive side though, doesn't it? Being that 12-18" is considered ideal.
Not really.
It's important to remember what's behind the 12-18".
Less than 12" is bad, as the vitals may not be reached in all cases.
More than 18" is OK, but not optimal.
That extra penetration energy is usually better used to expand the bullet wider or sooner and create a wider damage path.
In the case of these TTSX, the deep penetration is more a result of the high retained weight vs failure to expand soon enough or wide enough.
These expand to nearly double caliber within 1", so it's hard to make the argument that there is much, if any performance left on the table.
Their average penetration is only slightly deep (still under 20" ) and they don't exhibit any other sub-optimal traits, so I'd say they are excellent.
vicious_cb
01-01-12, 00:29
Maybe in Call of Duty: Modern Warfare but not in the real world. Nevermind the fact that the 5.56 bullet wouldn't have enough velocity at 1000 yards to frag or cause much more than a .22 caliber wound track with very little stretch cavity, but even an EXPERT Marine Sniper would have a VERY difficult time getting the 5.56 on a man sized target at a 1000 yards. A Hornady 75 gr BTHP match bullet (BC .395) with a generous muzzle velocity of 2700fps will have dropped 455 inches at 1000 yards and even the slightest wind will blow it severely off course at anything over 500 yards.
By the way, the Army means "effective" in that it will neutralize a human target at that range.
Reading comprehension, no where do I advocate using 5.56 at that distance nor do I say its even effective. Your previous post tells me you somehow think 5.56 turns into a spitwad past 500 yards and that getting people to drop at that distance is "wishful thinking". That is completely false, there are people on this forum who have slain past 600m with 5.56 or know some who has. Assuming my firearms experience comes from a video game and reading your little range card off in an attempt to belittle someone doesnt fly on this forum.
http://cdn.pimpmyspace.org/media/pms/c/1b/xa/tk/bestfranz.gif
AAAND now the internet is back...:rolleyes:
5.56 will still be deadly past 1000 yards even long after if falls to sub sonic speed.
Blame it on my reading comprehension but I think most folks would think "deadly" means "effective".
and reading your little range card off in an attempt to belittle someone doesnt fly on this forum.
"A lot of people" and "this guy one time" may work for you, but my "little range card" is based on physics. It uses the ballistic coefficient of a known bullet, the muzzle velocity in fps, a 50 yard zero and 1.5 inch sight height.
Please pardon my reference to Call of Duty, but I really thought that anyone coming onto a Terminal Ballistics forum and claiming the 5.56 was a viable cartridge at 1000 yards was A) a teenager having fun on the internet, B) someone obviously joking, C) a troll trying to start an argument or D) someone totally out of touch with reality. The fact it wasn't a typo and you are actually claiming the 6.8 somehow has LESS range than 5.56 is just nuts.
My qualifications are past military experience and 6 years on my Police Tactical Team. You can rest assured that we did not employ 5.56 for any applications more than 100 yards if we could help it. Our standard issue "perimeter gun" was an H&K G3 chambered in .308.
I am fairly new on this forum but have years of posts on that "other" forum. I don't really know you but past experience tells me the better part of discretion means this will be my last response to your posts.
Leatherneck556
01-01-12, 05:18
Blame it on my reading comprehension but I think most folks would think "deadly" means "effective".
Obtaining fragmentation or expansion is ideal, but poking a .22" hole in a vital structure is still plenty deadly. Is a .22lr deadly? Absolutely. Is it effective? No, not really.
"A lot of people" and "this guy one time" may work for you, but my "little range card" is based on physics. It uses the ballistic coefficient of a known bullet, the muzzle velocity in fps, a 50 yard zero and 1.5 inch sight height.
Please pardon my reference to Call of Duty, but I really thought that anyone coming onto a Terminal Ballistics forum and claiming the 5.56 was a viable cartridge at 1000 yards was A) a teenager having fun on the internet, B) someone obviously joking, C) a troll trying to start an argument or D) someone totally out of touch with reality. The fact it wasn't a typo and you are actually claiming the 6.8 somehow has LESS range than 5.56 is just nuts.
My qualifications are past military experience and 6 years on my Police Tactical Team. You can rest assured that we did not employ 5.56 for any applications more than 100 yards if we could help it. Our standard issue "perimeter gun" was an H&K G3 chambered in .308.
I am fairly new on this forum but have years of posts on that "other" forum. I don't really know you but past experience tells me the better part of discretion means this will be my last response to your posts.
I assure you that the military's definition of "effective range" in the realm of small arms has a lot more to do with accuracy than effects on target. As a matter of fact, it specifically comes from a blend of accuracy, trajectory, and the ability of the shooter to accurately judge range. The M16 and M4 only have a "maximum effective range" out to 500m on a point target according to the USMC. One of the designated marksmen in my company last year got one or more confirmed kills out to somewhere between 600 and 800 with a Mk12.
As somebody who's not involved in your argument, I can say from the outside that it really seems like you're the one trolling by disrespectfully throwing around a lot of accusations, making claims as to your "qualifications", and disregarding real-world experiences. I'm just throwing that out there because I've learned in life that it's usually a lot better to deal with people respectfully and humbly; you'd do well to learn that same lesson.
Failure2Stop
01-01-12, 08:01
"A lot of people" and "this guy one time" may work for you, but my "little range card" is based on physics. It uses the ballistic coefficient of a known bullet, the muzzle velocity in fps, a 50 yard zero and 1.5 inch sight height.
You would have a lot more success if you used the actual sight height of an AR, which is between 2.6 and 3.25 inches (depending on optic/sighting system).
Anyway:
Biggest gripe with effective range with 5.56 is barrier penetration and wind effect. Newer, better, barrier blind ammo is reducing that barrier penetration issue, but you lose a lot of work potential at distances past 200 meters with the weights of 5.56 rounds, whereas upping the ante by the common weights of the intermediate calibers you retain more downrange energy, which equates to better barrier penetrating potential as well as the potential of creating larger wound channels, depending on round construction.
Exposed, unarmored threats are no problem at long range with 5.56 with a decent shooter, but add in the variables of combat and stepping up in caliber makes things easier. . .
if you can deal with the weight and recoil.
Failure2Stop
01-01-12, 08:21
I assure you that the military's definition of "effective range" in the realm of small arms has a lot more to do with accuracy than effects on target. As a matter of fact, it specifically comes from a blend of accuracy, trajectory, and the ability of the shooter to accurately judge range. The M16 and M4 only have a "maximum effective range" out to 500m on a point target according to the USMC.
I would like to know your reference for that data.
I spent a considerable amount of time trying to figure out where the "max eff" range came from.
In my research I found that it is came from a testing requirement that required a shooter to place 8 of 10 rounds on a 40" H x 20" W target at 550 meters using iron sights. There are details about the test that I can't remember, but it had nothing to do with terminal effect, range estimation, or trajectory. The max eff for an area target (which had no precision requirement) was based on the max range setting of the sights. When the detachable carry handles were brought into use the max eff area tgt dropped to 600, since it is the max range available on the rear sight.
There is discussion on changing the max eff point to 800 meters since the RCO provides the shooter the ability to accurately target an 800 meter threat.
I am working off of memory on the info about the max effective range, so specifics very well may be incomplete os imprecise, but the general gist of information is as correct as I can recall.
Leatherneck556
01-01-12, 08:46
You probably have better data on how max effective range is figured than I do. I haven't researched or seen specifics anywhere; I got my information from a few people that would be considered "authorities". Specifically, I got my information from some Gunners (the USMC chief warrant officer type, not the guy who pulls a trigger). A retired Gunner that works for the company who makes LAW Rockets had told me the part about range estimation/trajectory. Then again, Gunners create and propagate myths just as bad as anybody else who doesn't do all the necessary research, so I guess that's what I get for just accepting that. As for saying 500 instead of 550, that comes from trying to remember what I learned in boot camp (which was seven years ago) and not double checking my facts.
Foot in mouth! My bad. Thanks for the clarification on that one!
Microalign
01-01-12, 08:55
As I recall the M855 was adopted because it was able to punch through a GI steel helmet at 1200m. Therefore, in terms of being able to kill someone wearing heavy clothing and light armor the 5.56 is at least effective out to 1200m. I think there are far better choices than 5.56 if I chose to shoot anything beyond 400m though since all it is doing is punching .22" holes at that range.
As I recall the M855 was adopted because it was able to punch through a GI steel helmet at 1200m.
Not quite that far.
From wiki (http://en.wikipedia.org/wiki/5.56×45mm_NATO)
The SS109 used a heavier bullet with a steel core and had a lower muzzle velocity for better long-range performance, specifically to meet a requirement that the bullet be able to penetrate through one side of a steel helmet at 600 meters. This requirement made the SS109 (M855) round less capable of fragmentation than the M193 and was considered more humane[9]
From Ammo Oracle (http://ammo.ar15.com/ammo/project/term_762.html) and Global Security (http://www.globalsecurity.org/military/library/report/1986/MVT.htm)
The SS-109 can penetrate the 3.45mm standard NATO steel plate to 640 meters, while the 7.62mm ball can only penetrate it to 620 meters. The U. S. steel helmet penetration results are even more impressive as the SS-109 can penetrate it up to 1,300 meters, while the 7.62mm ball cannot penetrate it beyond 800 meters.
ETA: It looks like the numbers are all over the place.
Microalign
01-01-12, 10:24
Thanks for the clarification.
My apologies. I was somewhat distracted when I wrote that. I was going for "exsanguination", but instead went with the colloquial form of "asphyxiation". Anyway, blood loss.
As you say, I'm not quite sure how someone would suffocate as a result of a gunshot wound.
Double pneumothorax or destruction of the nerves innervating the diaphragm.
One of the designated marksmen in my company last year got one or more confirmed kills out to somewhere between 600 and 800 with a Mk12.
There is a big difference between 600 and 800 when ranging a target for 5.56. If he wasn't ranging at that distance, I'm curious how he compensated for the bullet drop, unless the target waited around for trial by shot, which is not uncommon at that distance. Just curious, how many designated marksmen in your company were taking shots over 1000 yards with 5.56, which was the topic of my response? We have different rules of engagement in the police realm. Using 5.56 for the ranges you guys are talking about would open you up for a lawsuit bigtime.
Exposed, unarmored threats are no problem at long range with 5.56 with a decent shooter, but add in the variables of combat and stepping up in caliber makes things easier. . .
if you can deal with the weight and recoil.
Excellent summary F2S!
As I recall the M855 was adopted because it was able to punch through a GI steel helmet at 1200m. Therefore, in terms of being able to kill someone wearing heavy clothing and light armor the 5.56 is at least effective out to 1200m.
What did the bullet do after going through the helmet? Without knowing that you can't really say it would be able to kill the wearer.
Double pneumothorax or destruction of the nerves innervating the diaphragm.
With those kind of injuries the likelihood of other severe injuries being present would be quite high, so I doubt that those would be the only injuries contributing to a persons death.
@Swatdude1:
Do you seriously doubt that a 5.56 will work past 300 meters?
What do you base this observation on?
Have you done any mathemathical calculations on this? Real life testing? Studied engagements done with 5.56 caliber rounds during OEF/OIF/ISAF missions/firefights?
Our Defence Research Institute has done some research in this area, and calculated the following:
A 7.62x51 FMJ (fired from a G3) can potentially kill a person at 4000 meters
A 5.56x45 FMJ (fired from a 14.5" C8 SFW) can potentially kill a person at 3000 meters
A 9x19 FMJ (fired from an MP-5A2/A3) can potentially kill a person at 1800 meters
There was a recent incident invovling a muzzle loader, an ND and an Amish girl dead as a result of a GSW to the head at 1.5 miles.
http://www.msnbc.msn.com/id/45738811/ns/us_news-life/
I know these are not realistic engagement ranges, but do not read too much into the effective and maximum ranges stated by military manuals.
These ranges are, as stated by others, an estimate as to how far a soldier can expect to hit point/are targets with basic rifle marksmanship skills. Has nothing to do with at what range a bullet is no longer capable of inflicting serious injury or death on a human being. Take the Germans during WW2, and how they used their MG42s for indirect fire up to 2000-3000 meters away.
In addition, there are enough anecdotal stories of long range engagements with 5.56, beyond 300-400 meters, to provide a hint of empirical evidence as to the effectiveness of the round at longer ranges.
thats pretty much it. If im engaging someone at 600yds, Sure fragging is REALLY nice, but if you put a hole in the head/heart, maybe even lungs, they are gonna be out of the fight. It will take longer, but the need to put them down NOW is not there.
bottom line is, 308 is probably the best all around cartridge for shot to shot performance and general purpose.
6.8 really good.
5.56 gets the job done and with ammo thats come out in the last 5-10 years, is very effective, but its not optimal. However, it offers more shots per weight, lower cost and less recoil. Ive read its easier to shoot at longer ranges than 6.8 but have never shot past 400 yds myself so I cant offer 1st hand opinions on it.
If you put the round where it should be, it will kill the target. A buddy of mine shot a deer at almost 1000yds with a 204 and killed it. Is it optimal? No but shot placement is key(and in this extreme case, luck was also key). Intermediate cartriges WILL not produce impressive wound tracts at 700yds. They are close range cartriges that CAN be stretched out to distance if needed, but will not be optimal. I think some people forget that sometimes.
@Swatdude1:
Do you seriously doubt that a 5.56 will work past 300 meters?
No, I don't doubt 5.56 will "work" past 300 meters. Go back and read my posts again.
I don't doubt that 5.56 could kill someone at 1000 yards, but the probability of hitting the target, much less hitting a vital structure, is SEVERELY diminished at this range.
Take the Germans during WW2, and how they used their MG42s for indirect fire up to 2000-3000 meters away.
I've never heard about that. Perhaps the subject of another thread someday.
No, I don't doubt 5.56 will "work" past 300 meters. Go back and read my posts again.
I don't doubt that 5.56 could kill someone at 1000 yards, but the probability of hitting the target, much less hitting a vital structure, is SEVERELY diminished at this range.
Well, I did, and you write:
I don't know of any 5.56 round that is effective at 600 yards and even when the Army listed the effective range as 470 yards, this was based on a 20 inche barrel and really wishful thinking IMO.
Maybe in Call of Duty: Modern Warfare but not in the real world. Nevermind the fact that the 5.56 bullet wouldn't have enough velocity at 1000 yards to frag or cause much more than a .22 caliber wound track with very little stretch cavity
By the way, the Army means "effective" in that it will neutralize a human target at that range.
Seems to me that you doubt the effectiveness of a 5.56 round, at least to a certain degree.
If you have a good rifle, with a proficient shooter, I believe you could have effective shots out to 800 meters. Not saying a 5.56 is optimal for that kind of work, but to write it off is a bit arrogant.
You can rest assured that we did not employ 5.56 for any applications more than 100 yards if we could help it. Our standard issue "perimeter gun" was an H&K G3 chambered in .308
I can hit targets out to 450 meters much easier with my HK416 with Comp M4 and 3 x Magnifier than I could with a G3. And I have two times the time on a G3 than I do the HK416.
I don't know of any 5.56 round that is effective at 600 yards and even when the Army listed the effective range as 470 yards, this was based on a 20 inche barrel and really wishful thinking IMO.
600 is twice is far as 300.
Well, I did, and you write:
Seems to me that you doubt the effectiveness of a 5.56 round, at least to a certain degree.
Yes I do. I doubt its performance outside of its optimum range. I am not the only one who holds this sentiment. According to military times, the 5.56 in the current military loads is a poor performer over 300m out of a 14.5 inch barrel.
I can hit targets out to 450 meters much easier with my HK416 with Comp M4 and 3 x Magnifier than I could with a G3. And I have two times the time on a G3 than I do the HK416.
That was my specific SWAT guidelines. LE requirements, civil liabilities and rules of engagement are different than the military. In fact, this is purely anecdotal, but on a callout I was on, one of our snipers engaged a target at about 60 yards with a 5.56 with open sights, instead of his scoped McMillan .308 due to the close proximity. The target had taken a hostage and was talking on the hostage phone, which was tan colored. Our sniper got the go ahead and took the shot, the 5.56 round fragged on the telephone mouthpiece and did not neutralize the target. Luckily, he used his own handgun to end his life at that moment instead of the life of the hostage. After that incident, the hostage phone was painted red and 5.56 was prohibited from any and all sniper use.
Ok, it seems like you have made up your mind, and won't accept any other arguments. Fine with me, as I know that you are severely underestimating the round.
Oh, yeah, I agree that the best thing to do after the call out you mentioned was to shit can the ammunition. After all, the failure to stop was not a marksmanship error at all.
I can hit targets out to 450 meters much easier with my HK416 with Comp M4 and 3 x Magnifier than I could with a G3. And I have two times the time on a G3 than I do the HK416.
What do you feel are the primary factors that account for these easier hits?
Recoil, controllability, platform, action, free float, optics?
What do you feel are the primary factors that account for these easier hits?
Recoil, controllability, platform, action, free float, optics?
It has a lower recoil impulse, more controllable when firing rapid shots in succession, better trigger (in my opinion, I know some folks who hate the trigger on the HK416 and prefer the one on the G3).
I also feel it is easier to get into a good shooting position with this rifle, than with the G3. It is shorter, more manageable, you can adjust LOP to suit your body type. The G3 is 102cm long no matter what you do, and the stock is the same lenght. We did get upgrades for our G3's, including a 3 pos retractable stock, but that stock isn't particularly suited for long range shooting.
As far as the optics go, I'm not sure actually. The Comp M4 is capable, no issue there. I just haven't tried the irons out to that range. The rear BUIS we have is really crap.
And of course, the 3 x magnifier helps with observing bullet impact so I can adjust my holds accordingly.
That was my specific SWAT guidelines. LE requirements, civil liabilities and rules of engagement are different than the military. In fact, this is purely anecdotal, but on a callout I was on, one of our snipers engaged a target at about 60 yards with a 5.56 with open sights, instead of his scoped McMillan .308 due to the close proximity. The target had taken a hostage and was talking on the hostage phone, which was tan colored. Our sniper got the go ahead and took the shot, the 5.56 round fragged on the telephone mouthpiece and did not neutralize the target. Luckily, he used his own handgun to end his life at that moment instead of the life of the hostage. After that incident, the hostage phone was painted read and 5.56 was prohibited from any and all sniper use.
I would like some details about this incident if possible. In particular what ammo was being used. I wouldn't think this would be an issue with proper bonded ammo.
I'm also curious why your sniper would choose an iron sighted rifle of any kind for a precision shot, even at 60 yards. Do they not practice taking shots at that range with the scoped 308's? Statistics seem to show that most SWAT sniper shots are withing 100 yards so I would have thought that would be a well practiced range.
Feel free to PM me if you'd rather discuss it privately. I can also provide my LE contact email address if you are more comfortable with that on PM.
Ok, it seems like you have made up your mind, and won't accept any other arguments. Fine with me, as I know that you are severely underestimating the round.
Oh, yeah, I agree that the best thing to do after the call out you mentioned was to shit can the ammunition. After all, the failure to stop was not a marksmanship error at all.
While I would agree that banning .223 for sniper use was probably a knee jerk reaction (Police agencies are well known for that), I would definitely at least look into changing ammunition type. A round that will fragment on a plastic phone handset and fail to penetrate raises some pretty serious concerns. It could be a fluke, but I'd want to make sure.
CumbiaDude
01-02-12, 19:40
A round that will fragment on a plastic phone handset and fail to penetrate raises some pretty serious concerns. It could be a fluke, but I'd want to make sure.The way I pictured it, the phone was held to the side of the guy's head (from sniper's perspective), and the shot was placed too far to the side (hitting the phone instead of the person). It seems you think it was supposed to go through the phone and into the person, but failed to penetrate enough. Two different scenarios. Which was it that happened? It'd be good to get some clarification on this.
I would like some details about this incident if possible. In particular what ammo was being used. I wouldn't think this would be an issue with proper bonded ammo.
I'm also curious why your sniper would choose an iron sighted rifle of any kind for a precision shot, even at 60 yards. Do they not practice taking shots at that range with the scoped 308's? Statistics seem to show that most SWAT sniper shots are withing 100 yards so I would have thought that would be a well practiced range.
Feel free to PM me if you'd rather discuss it privately. I can also provide my LE contact email address if you are more comfortable with that on PM.
I am comfortable discussing it here. It was 16 years ago and my department was Tempe Police. Bonded bullets weren't seeing use yet. To be honest, I can't remember what 5.56 ammo we were using at the time. The suspect was in the rear room of a condo and we were in the house across the alley behind. I was just guessing 60 yards but it could have well been less. The answer to your question about praciticing scoped shots at that range is yes. But the way the suspect was pacing back and forth frantically made it almost impossible for our sniper to keep him in the FOV of his scope at that close range so he made the decision to go to open sights with the only weapon available at the time, a colt CAR15-A3.
The round actually fragged on the hostage phone mouthpiece. A barrier blind round like Doc Roberts advocates for LE use in his 6.8 presentation I have viewed, would have done the job, as would the .308 round we were using at the time.
About the time I was leaving the team in 1999, we abandoned our MP-5's and replaced them with suppressed, 12-inch barrelled Colt AR-15's. This was after several incidents where the 9mm severely overpenetrated drywall prompting testing on the 9mm vs. the 5.56. The 5.56 was found to easily penetrate body armor, a big concern with the 9mm after the North Hollywood shootout, but actually penetrated fewer panels of drywall in testing.
I still think that the 5.56 is a great round for entry applications. I guess this thread got derailed when I was shocked that anyone would advocate using 5.56 at the distances they were speaking of when there are so many better options for those long ranges. The only application for a 1000 yard shot I think would be a military one and the question I have is are our soldiers really being asked to engage targets at those distances with a 5.56?
The way I pictured it, the phone was held to the side of the guy's head (from sniper's perspective), and the shot was placed too far to the side (hitting the phone instead of the person). It seems you think it was supposed to go through the phone and into the person, but failed to penetrate enough. Two different scenarios. Which was it that happened? It'd be good to get some clarification on this.
I didn't actually witness the shot, but the way the officer explained it to me was he could see he was on the hostage phone as his hand was holding it up but he couldn't see that it was in front of his mouth. He was aiming for the trapezoid but the trajectory of the round would have impacted his upper lip had it not encountered the metal mouthpiece in the receiver.
CumbiaDude
01-02-12, 22:00
Gotcha. Sounds like more of a "quartering" shot. Either way, not what I was picturing. I thought it was a miss (cuz he aimed at the phone, thinking it was a part of the guy's head), but in reality he aimed at the head and the phone piece interfered.
Thanks for the added detail :)
Gotcha. Sounds like more of a "quartering" shot. Either way, not what I was picturing. I thought it was a miss (cuz he aimed at the phone, thinking it was a part of the guy's head), but in reality he aimed at the head and the phone piece interfered.
Thanks for the added detail :)
Yes, the officer was attempting a front headshot. The suspect had a 9mm handgun trained on the hostage (his girlfriend) and was threatening to kill her. Almost immediately after being hit in the mouth, instead of killing her, he put the 9mm into his mouth and pulled the trigger, ending his own life.
I am comfortable discussing it here. It was 16 years ago and my department was Tempe Police. Bonded bullets weren't seeing use yet. To be honest, I can't remember what 5.56 ammo we were using at the time. The suspect was in the rear room of a condo and we were in the house across the alley behind. I was just guessing 60 yards but it could have well been less. The answer to your question about praciticing scoped shots at that range is yes. But the way the suspect was pacing back and forth frantically made it almost impossible for our sniper to keep him in the FOV of his scope at that close range so he made the decision to go to open sights with the only weapon available at the time, a colt CAR15-A3.
The round actually fragged on the hostage phone mouthpiece. A barrier blind round like Doc Roberts advocates for LE use in his 6.8 presentation I have viewed, would have done the job, as would the .308 round we were using at the time.
About the time I was leaving the team in 1999, we abandoned our MP-5's and replaced them with suppressed, 12-inch barrelled Colt AR-15's. This was after several incidents where the 9mm severely overpenetrated drywall prompting testing on the 9mm vs. the 5.56. The 5.56 was found to easily penetrate body armor, a big concern with the 9mm after the North Hollywood shootout, but actually penetrated fewer panels of drywall in testing.
I still think that the 5.56 is a great round for entry applications. I guess this thread got derailed when I was shocked that anyone would advocate using 5.56 at the distances they were speaking of when there are so many better options for those long ranges. The only application for a 1000 yard shot I think would be a military one and the question I have is are our soldiers really being asked to engage targets at those distances with a 5.56?
Thanks for the detail. That makes alot more sense now and actually dovetails nicely into a discussion I was having with some non-LEO friends of mine that seem bent on getting the highest possible magnification for their AR optics.
Sure it works fine for shooting from the bench at static targets and is better for shooting at 500 yards but if your expected engagement distance is 50 yards or less it isn't such a great idea.
I'm Ok with 5.56 ballistics discussions, even heated ones, but in this thread?
Seems like it's related, but we're way off on a tangent right now with very little linkage back to the original topic of bigger than 5.56 being relevant.
I'm Ok with 5.56 ballistics discussions, even heated ones, but in this thread?
Seems like it's related, but we're way off on a tangent right now with very little linkage back to the original topic of bigger than 5.56 being relevant.
You are correct. To bring this back on topic I've heard the argument that 6.8 (or 6.5) could fill both patrol rifle and sniper rolls in an LE context, allowing a department to buy one platform and one ammunition type across the board. It would provide improved terminal and barrier performance over 5.56 while providing sufficient performance for sniper engagements at the typical LE engagement distances (under 100 yards). Had this been the case with the incident being discussed both the scoped gun and the open sighted gun would have been a 6.8 and the phone would not have been an issue (though it probably would not have been with modern bonded ammo in 5.56 either).
I see the validity of the argument and could see an intermediate caliber filling this role well. The hang ups would be cheap practice ammo (always a difficult hurdle) and snipers are very much married to the .308. It is hard enough to convince them to leave the 168gr SMK or switch to semi-autos, much less changing to a smaller caliber and smaller platform.
You are correct. To bring this back on topic I've heard the argument that 6.8 (or 6.5) could fill both patrol rifle and sniper rolls in an LE context, allowing a department to buy one platform and one ammunition type across the board. It would provide improved terminal and barrier performance over 5.56 while providing sufficient performance for sniper engagements at the typical LE engagement distances (under 100 yards). Had this been the case with the incident being discussed both the scoped gun and the open sighted gun would have been a 6.8 and the phone would not have been an issue (though it probably would not have been with modern bonded ammo in 5.56 either).
I see the validity of the argument and could see an intermediate caliber filling this role well. The hang ups would be cheap practice ammo (always a difficult hurdle) and snipers are very much married to the .308. It is hard enough to convince them to leave the 168gr SMK or switch to semi-autos, much less changing to a smaller caliber and smaller platform.
This is a great point. Other than some rural applications in the great plains maybe, I can't see any police engagement ever happening past 300 yards, or at least a very low, low probability of it occurring. Seems like the 6.8 would be all that was needed. Also, training with a 5.56 upper is always an option, with slightly more recoil being the only variable.
This is a great point. Other than some rural applications in the great plains maybe, I can't see any police engagement ever happening past 300 yards, or at least a very low, low probability of it occurring. Seems like the 6.8 would be all that was needed. Also, training with a 5.56 upper is always an option, with slightly more recoil being the only variable.
Phx PD supposedly has the longest police shooting at around 320 yards up by Lake Pleasant. It was a homicide suspect who was in a high speed chase/shoot out and crashed up in the hills where he continued to shoot at pursuing officers. A patrol officer then shot him using an iron sighted 20" Colt Hbar.
Reading through the thread I still think that a good barrier blind 5.56 is ideal for standard rifleman. It has improved terminal performance at range, low recoil and low weight.
I do think that the 6.8 would make a fantastic law enforcement sniping round. A good barrier blind load in a Mk12 or Recce type rifle would fit then need just about perfectly.
Phoenix SAU (SWAT) tested the POF shorty .308 but found it to be unreliable. They did like the small package though and it was very accurate.
Phoenix SAU (SWAT) tested the POF shorty .308 but found it to be unreliable. They did like the small package though and it was very accurate.
I own a POF .308 and I am fairly confident I got to the bottom of this rumor. I actually spoke with the Phoenix SAU Lt. who said they had no problems with their POF. Frank from POF seems to echo this. I really would be curious to know the source of your information because it was POF's forum behaviour that prompted me to call Phx PD initially. See below:
http://www.ar15.com/forums/t_2_206/206350_Why_would_POF_delete_the_thread_.html
Scroll to three posts at the bottom...
http://www.ar15.com/forums/t_2_206/188475_POF_on_duty_with_City_of_Phoenix.html&page=2
Zak Smith has written the most comprehensive and accurate article on the history, genesis, and development of the 6.8 mm SPC that I have yet publicly encountered: http://demigodllc.com/articles/6.8-mm-spc-cartridge-history-development-hornady-stag-arms-carbine Highly recommended!
In our experience, 6.8 mm external ballistics are on par with 5.56 mm, however 6.8 mm terminal ballistics are superior, as noted on pages 13-19 here: http://www.dtic.mil/ndia/2008Intl/Roberts.pdf.
Take a close look at page 15: http://www.dtic.mil/ndia/2004arms/session9/minisi.ppt; this directly addresses the official Army estimation of effectiveness of the 5.56 mm M855 when fired from the M16, M4, and Mk18. Looks like the Mk18/M855 offers acceptable terminal effects to about 25m, M4/M855 to 125m, M16/M855 to 200m. If Mk262 is substituted for M855, then the Army data notes that Mk18/Mk262 offers acceptable terminal performance to around 65m; M4/Mk262 to 175m; M16/Mk262 to 250m or so.
Accuracy is important at longer ranges. If you don’t hit the target, you get NO physiological incapacitation effects. Look at the difference in hit potential at distance between M855 and Mk262 as illustrated on pages 7 and 8 of this presentation: http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&sqi=2&ved=0CCUQFjAB&url=http%3A%2F%2Fwww.dtic.mil%2Fndia%2F2003smallarms%2Fbux.ppt&ei=_aoET7DIEYeViAKtuvmmDg&usg=AFQjCNHOMek9zPA_UTI8vkdNgz5WL9gsbA. I personally know individuals who have made confirmed effective incapacitating hits on terrorist personnel in OCONUS combat using Mk262 out of Mk12’s at ranges from 600-800. Having said that, 5.56 mm is NOT an optimal caliber for such engagements. A combat experienced SOF NCO has recently commented: "If it is a precision shot, more than 250 out, and it doesn't have 4 legs, live in a hole, and do somersaults when it gets hit by 556, then I go ahead and move onto the .300 Win Mag and leave the little bullets for other things.. Likewise, Kyle Defoor has written https://www.m4carbine.net/showthread.php?p=792292:
”As has been pointed out 5.56 does fine in moderate wind out pretty far. There are an assload of guys both Army and Navy that have slayed past 600 repeatedly.
For pickin and choosin I tell guys the rules of 4 for caliber:
400 and closer: 5.56mm all day
400-800: 7.62mm
800-1200: 300 WM
1200-1600: 338 Lapua
I said a few years ago that bolt action sniper guns would become obsolete at close and moderate distances. I got laughed at. Well, a good friend of mine who I shot with during 2 courses this year and his shooting partner just won the International Sniper Competition at Benning with Larue OBRs.”
I own a POF .308 and I am fairly confident I got to the bottom of this rumor. I actually spoke with the Phoenix SAU Lt. who said they had no problems with their POF. Frank from POF seems to echo this. I really would be curious to know the source of your information because it was POF's forum behaviour that prompted me to call Phx PD initially. See below:
http://www.ar15.com/forums/t_2_206/206350_Why_would_POF_delete_the_thread_.html
Scroll to three posts at the bottom...
http://www.ar15.com/forums/t_2_206/188475_POF_on_duty_with_City_of_Phoenix.html&page=2
I was told about the POF 308 by one of our SAU snipers about 6 months ago down at the ALEA range. I was asking about their recent purchase of POF sbr entry guns. He said they were working very well but that the shorty 308 was having reliability problems when it got fouled up from shooting.
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