View Full Version : Solid Copper and Bonded Rifle Bullets Produce Less Wound Trauma?
Shawn Dodson
12-04-11, 07:58
It seems to me that solid copper rifle bullets, like those offered by Barnes, and bonded lead-core rifle bullets don't produce the same amount of wound trauma as conventional unbonded lead-core expanding rifle bullets, because the former do not shed lead fragments as they expand, which pepper surrounding tissues with small holes that are then torn open by the subsequent temorary cavity.
All seem to produce similar sized temporary cavities, which may or may not cause soft tissues to tear, however the amount of permanent disruption appears greater for conventional unbonded lead-core because solid copper and bonded lead-core rifle bullets merely expand whereas conventional unbonded lead-core expand AND fragment. The fragments work in synergy with the temporary cavity to tear and detach soft tissues.
Given a choice between a 5.56/223 load that uses Nosler 60gr Partition and a load that uses Barnes 50gr TSX, it appears to me that the Nosler will produce greater wound trauma than the Barnes.
Am I missing something?
It seems to me that solid copper rifle bullets, like those offered by Barnes, and bonded lead-core rifle bullets don't produce the same amount of wound trauma as conventional unbonded lead-core expanding rifle bullets, because the former do not shed lead fragments as they expand, which pepper surrounding tissues with small holes that are then torn open by the subsequent temorary cavity.
All seem to produce similar sized temporary cavities, which may or may not cause soft tissues to tear, however the amount of permanent disruption appears greater for conventional unbonded lead-core because solid copper and bonded lead-core rifle bullets merely expand whereas conventional unbonded lead-core expand AND fragment. The fragments work in synergy with the temporary cavity to tear and detach soft tissues.
Given a choice between a 5.56/223 load that uses Nosler 60gr Partition and a load that uses Barnes 50gr TSX, it appears to me that the Nosler will produce greater wound trauma than the Barnes.
Am I missing something?
I'm by no means an expert, however I would suppose that because the fragments when they shear off will be traveling at far less velocity with far less energy, are going to produce less trauma to tissue than you think.
If we suppose a resistance value of R for tissue, then to overcome 1cm of tissue, the lead fragments would be robbed of R amount of energy as it overcomes it (It takes X amount of energy to overcome R resistance, so a value of X(t) is reduced by X(r) per CM of penetration).
So, if that's the case, it seems to me that fragments with very little mass would have equally little momentum value, and would very quickly lose energy overcoming tissue.
A bonded bullet, on the other hand (or a solid copper), is going to do more damage, in my opinion, because theoretically it retains its mass, and therefore its momentum, and loses less energy per CM of penetration due to loss of momentum, and would maintain its temporary cavitation longer and penetrate deeper.
From my experience in hunting, this is held up in the real world where bonded core bullets seem to more uniformly penetrate more deeply than traditional lead core, and in more cases, anecdotally, cause more traumatic damage.
It seems to me that solid copper rifle bullets, like those offered by Barnes, and bonded lead-core rifle bullets don't produce the same amount of wound trauma as conventional unbonded lead-core expanding rifle bullets, because the former do not shed lead fragments as they expand, which pepper surrounding tissues with small holes that are then torn open by the subsequent temorary cavity.
All seem to produce similar sized temporary cavities, which may or may not cause soft tissues to tear, however the amount of permanent disruption appears greater for conventional unbonded lead-core because solid copper and bonded lead-core rifle bullets merely expand whereas conventional unbonded lead-core expand AND fragment. The fragments work in synergy with the temporary cavity to tear and detach soft tissues.
Given a choice between a 5.56/223 load that uses Nosler 60gr Partition and a load that uses Barnes 50gr TSX, it appears to me that the Nosler will produce greater wound trauma than the Barnes.
Am I missing something?
I don't think so.
I shoot a lot of large game and this attribute is why I have gone to the solid copper alloy projectiles. In the past, have used the Remington Core-Lokt and observed greater disruptive effect earlier in the wound track than I've seen in the homogenuous alloy projectiles like the TSX. I like them because they destroy less meat should they strike a ham or tenderloin.
While I've often recovered spent Core-Lokts typically in less than 24" worth of travel inside the game animal, I've have yet to recover a homogenuous alloy design under any circumstance save for two from the same animal- a pair of Winchester .30-06 180 gr. Failsafe JHPs from a somewhat largish 43" Cape Buffalo shot lengthwise in Tanzania in late 2002. (This little stunt was done with the TGA's permission)
Recovered dimensions were nearly identical-
1.) avg RD: 0.375" (0.405" x 0.344") RW: 149.9 gr. RL: 0.834"
2.) avg RD: 0.376" (0.407" x 0.345") RW: 148.1 gr. RL: 0.826"
Penetration was ~48" IIRC, but I didn't take terminal penetration measurements since it was getting dark and we didn't want to stay in the mopane longer than necessary with all that blood and meat.
I agree with DeltaKilo- less work done by the bullet to the target per unit distance of travel means that penetration depth necessarily increases.
It seems to me that solid copper rifle bullets, like those offered by Barnes, and bonded lead-core rifle bullets don't produce the same amount of wound trauma as conventional unbonded lead-core expanding rifle bullets, because the former do not shed lead fragments as they expand, which pepper surrounding tissues with small holes that are then torn open by the subsequent temorary cavity.
All seem to produce similar sized temporary cavities, which may or may not cause soft tissues to tear, however the amount of permanent disruption appears greater for conventional unbonded lead-core because solid copper and bonded lead-core rifle bullets merely expand whereas conventional unbonded lead-core expand AND fragment. The fragments work in synergy with the temporary cavity to tear and detach soft tissues.
Given a choice between a 5.56/223 load that uses Nosler 60gr Partition and a load that uses Barnes 50gr TSX, it appears to me that the Nosler will produce greater wound trauma than the Barnes.
Am I missing something?
No I don't think you are missing anything. I think the answer is simply that any bullet choice is a compromise between maximum tissue disruption on an unobstructed target, and effective real world performance under difficult conditions.
I think that the Nosler 60gr vs 50gr TSX is not so much of an issue. The entire Nosler bullet weighs 60gr with the front core accounting for less than half the weight. Most of the gel tests I have seen show recovered weights in the low 50gr range so you are getting a whopping 10gr of fragments at best in the entire wound channel. Either load is acceptable for general barrier blind use.
The big question comes when we compare something like 75gr OTM loads that show massive ammounts of fragmentation vs. a Barnes TSX bullet. In this case as Dr. Roberts has mentioned earlier the OTM is fine for unobtructed shot, but what happens when the bad guy decides to take cover. A general purpose defensive load must work under all conditions expected to be encountered. Despite what the gelatin tests show (12"+ penetration) if an OTM penetrates an outstretched arm it may begin to fragment in the arm. The fragments exiting the arm will have to deal with the "holdback effect" of the arm skin, any clothing the subject is wearing (sleeves and torso covering), and then penetrate into the vitals. A single bonded projectile will have a much greater chance of achieveing this.
.223/5.56 due to the light weight of the projectiles requires such compromises to be made. If we step up to .308 we can get loads that can afford to shed fragments yet still will penetrate any common barrier with enough authority to still penetrate into the vitals.
No I don't think you are missing anything. I think the answer is simply that any bullet choice is a compromise between maximum tissue disruption on an unobstructed target, and effective real world performance under difficult conditions.
I think that the Nosler 60gr vs 50gr TSX is not so much of an issue. The entire Nosler bullet weighs 60gr with the front core accounting for less than half the weight. Most of the gel tests I have seen show recovered weights in the low 50gr range so you are getting a whopping 10gr of fragments at best in the entire wound channel. Either load is acceptable for general barrier blind use.
The big question comes when we compare something like 75gr OTM loads that show massive ammounts of fragmentation vs. a Barnes TSX bullet. In this case as Dr. Roberts has mentioned earlier the OTM is fine for unobtructed shot, but what happens when the bad guy decides to take cover. A general purpose defensive load must work under all conditions expected to be encountered. Despite what the gelatin tests show (12"+ penetration) if an OTM penetrates an outstretched arm it may begin to fragment in the arm. The fragments exiting the arm will have to deal with the "holdback effect" of the arm skin, any clothing the subject is wearing (sleeves and torso covering), and then penetrate into the vitals. A single bonded projectile will have a much greater chance of achieveing this.
.223/5.56 due to the light weight of the projectiles requires such compromises to be made. If we step up to .308 we can get loads that can afford to shed fragments yet still will penetrate any common barrier with enough authority to still penetrate into the vitals.
I agree, 100%.
I agree, 100%.
In the original reply your contention was that bonded bullets cause more damage than a convention copper/lead non-bonded load.
This is counter to what bernieb90 just wrote (which was very well written by the way).
I won't attempt to address your formula, since even simple math is over my head, but how to you account for the substantial damage an OTM bullet causes while fragmenting massively, given your assertion that the lead fragments lose their effectiveness so quickly overcoming tissue resistance? It's possible I may be misinterpreting you here.
Robb Jensen
12-05-11, 05:16
News to me that bonded isnt as good.
I've shot 7 deer with Federal Fusion 165gr bonded .30-06 and every wound channel looked far better than any other .30-06 load I've ever used or seen used. All the Fusion shots were 1 shot stops and all completely existed the body. The wound channels usually look like I've used a larger or much faster caliber.
In the original reply your contention was that bonded bullets cause [b]more[b] damage than a convention copper/lead non-bonded load.
This is counter to what bernieb90 just wrote (which was very well written by the way).
I won't attempt to address your formula, since even simple math is over my head, but how to you account for the substantial damage an OTM bullet causes while fragmenting massively, given your assertion that the lead fragments lose their effectiveness so quickly overcoming tissue resistance? It's possible I may be misinterpreting you here.
If you reread what I said, and what bernie said, neither contradicts the other. My assertion is that, based solely on the physics, fragments will not necessarily penetrate a great deal. I also point out that a bonded/solid copper bullet will, theoretically penetrate to a greater degree due to a lower loss of momentum due to loss of mass.
I think the balancing point here is in the comparative effects of a deeper wound channel of some nonzero amount, compared to the potential increase of trauma caused by fragments of the bullet. Based on what I have observed, the deeper wound channel is more beneficial, however this does not preclude the potential for bullet fragments to add to the wound's effectiveness, either.
In any case, bernie's well-written post speaks well to the realities that choosing an effective load is a compromise between terminal effects and intermediate barriers, so, while I may hold my own theories on whether fragmentation plays as large of a part in effectiveness as is supposed (and i'm by no means an expert, so I can only go by observational data), bernie's post is absolutely right.
News to me that bonded isnt as good.
I've shot 7 deer with Federal Fusion 165gr bonded .30-06 and every wound channel looked far better than any other .30-06 load I've ever used or seen used. All the Fusion shots were 1 shot stops and all completely existed the body. The wound channels usually look like I've used a larger or much faster caliber.
This has been my experience as well.
From everything I've read from Fackler and Roberts, this is what I've interpreted the info to mean:
Bonded ammo produces great wounding capabilities AND allows barriers to be penetrated without severely reducing the capability to incapacitate a threat that is behind said cover.
Unbonded projectiles produce better results for exposed targets as the fragmenting is the best wounding mechanism. However, when shooting through intermediate barriers, these projectiles are damaged to the point that wounding capabilities are greatly compromised.
For long range shots and home defense type roles, heavy OTMs rule. For general combat and LEOs who are around vehicles and such, bonded projectiles and solid copper bullets like tsx-x are best as they still provide great term ballistics on bare targets and on targets that may need to be penetrated AFTER penetrating a barrier such as a car door, auto glass, walls, etc.
News to me that bonded isnt as good.
I've shot 7 deer with Federal Fusion 165gr bonded .30-06 and every wound channel looked far better than any other .30-06 load I've ever used or seen used. All the Fusion shots were 1 shot stops and all completely existed the body. The wound channels usually look like I've used a larger or much faster caliber.
I would think ammunition choice has less (obviously still important, but not to quite the same extent) of an impact once one moves up to 308 or larger. 223/5.56 is where ammo choice is critical.
That said, If you use any of the recommended loads, I doubt you would tell the difference if you had to use it. There is a pig hunting thread going on right now and people have dropped hogs using both OTMs and bonded ammo. Any expanding or fragmenting bullet going through the vitals will effectively remove them and result in very fast incapacitation.
I've shot quite a few deer with my 7mag using either 150gr Nosler Ballistic Tips, or 140gr Barnes TSXs. The former partially fragment and make a real mess. This is great if you have a good shot and hit them where it counts; the fragmentation puts them down HARD. The TSX's also work great, and you don't have to worry about the bullet blowing up if it hits a shoulder.
Hit the deer where it counts with either, and they'll go down. Personally, I think a partially fragmenting bullet like the BT's, SST's, etc. will take a deer down a little faster due to the overall damage.
The synergistic effects of rifle projectile fragmentation on PC and TC formation are discussed in the last paragraph here: https://www.m4carbine.net/showthread.php?t=34714.
The problems arise when the bullet remains point forward during tissue and fails to upset, yaw, and fragment in tissue--then you have a similar wound to that created by a deep puncture wound from an ice pick or arrow mounted with a traditional target point. In addition, most fragmenting projectiles do not fair well in tissue after first encountering an intermediate barrier since they lose too much mass, fail to penetrate deeply enough, and often deviate from the shot line. In essence, the fragmenting terminal effects can be INCONSISTENT.
On the other hand, barrier blind projectiles offer more CONSISTENT terminal performance across a wide spectrum of engagement scenarios. Considering that barrier blind projectiles do not penetrate any more deeply than quality service caliber handgun ammunition, misplaced concerns about "over-penetration" are moot. In addition, since most of the blind to barrier projectiles are newer designs, they have been optimized to offer ideal terminal performance characteristics (https://www.m4carbine.net/showthread.php?t=22323):
-- Full reliability in diverse environmental extremes
-- A thermally stable propellant
-- Consistent lot-to-lot and shot-to-shot performance, even when fired from short barrel weapons
-- Crimped and sealed primer
-- Sealed case mouth
-- Cannelure for functional reliability in adverse conditions
-- Decreased muzzle flash
-- Sufficient accuracy to hit threat targets out to 600m
-- Consistent terminal performance to 300m
-- No deviation from shot line after impact
-- Good projectile weight retention
-- Blind to Barriers
-- No AOA and fleet yaw impact variations
-- 12-18 inches of penetration
-- Maximized tissue damage during the first 12 inches of travel in tissue
-- Early consistent bullet upset within 1 or 2 inches of initial tissue penetration
It is hard to understand why someone would NOT want to go with a barrier blind projectile for duty/self-defense use.
Thanks, Doc.
I suppose I underestimated the efficacy of fragmentation in bare wounds, from a hunting perspective.
Except for hunting non-edible varmints, I would not want any fragments left in any animal destined to become dinner, as I hate people breaking teeth...
Except for hunting non-edible varmints, I would not want any fragments left in any animal destined to become dinner, as I hate people breaking teeth...
Well, there's that
I do nearly all my hunting with bonded or monometallic bullets. They work, and destroy very little tissue outside of the projectile track.
Except for hunting non-edible varmints, I would not want any fragments left in any animal destined to become dinner, as I hate people breaking teeth...
I've never had that problem FWIW - not saying it couldn't happen of course. Since the price of processing has gone way up, I now butcher my own animals. If you hit them in the chest, you're generally not going to have any residual fragments end up in meat you'd end up eating - unless you keep the rib meat.
[ETA] My comments in the previous post in regard to slightly preferring the Ballistic Tips to the TSX's only apply to large-caliber hunting of animals.
Thanks, Doc.
I suppose I underestimated the efficacy of fragmentation in bare wounds, from a hunting perspective.
I'm sorry, I meant to say "from a self defense perspective".
I suppose for the non-edible varmints, where barriers are not an issue, having tons of shrapnel will be more beneficial.
It seems to me that solid copper rifle bullets, like those offered by Barnes, and bonded lead-core rifle bullets don't produce the same amount of wound trauma as conventional unbonded lead-core expanding rifle bullets, because the former do not shed lead fragments as they expand, which pepper surrounding tissues with small holes that are then torn open by the subsequent temorary cavity.
All seem to produce similar sized temporary cavities, which may or may not cause soft tissues to tear, however the amount of permanent disruption appears greater for conventional unbonded lead-core because solid copper and bonded lead-core rifle bullets merely expand whereas conventional unbonded lead-core expand AND fragment. The fragments work in synergy with the temporary cavity to tear and detach soft tissues.
Given a choice between a 5.56/223 load that uses Nosler 60gr Partition and a load that uses Barnes 50gr TSX, it appears to me that the Nosler will produce greater wound trauma than the Barnes.
Am I missing something?
Yes, you are missing that fragmentation isn't all that reliable.
Folks over in the sandbox that are shooting bad men with the 70gr TSX advise me that it works very well.
C4
Yes, you are missing that fragmentation isn't all that reliable.
Folks over in the sandbox that are shooting bad men with the 70gr TSX advise me that it works very well.
C4
... and the 77 grain MK262 also works well, but if you look at DocGKR's info, you will see a yaw at 7" with that round and a 3" yaw of the TSX ... Bin Laden would agree that the TSX is an effective round.
So i think we can summerize this down to say that fragmentation, while offering some level of benefit, is not of enough benefit to absolutely drown out all of the drawbacks possible with loads that fragment and that any loss of effectiveness sustained by going with a bonded bullet or solid copper bullet is inconsequential compared to the benefits of utilizing such a load.
So i think we can summerize this down to say that fragmentation, while offering some level of benefit, is not of enough benefit to absolutely drown out all of the drawbacks possible with loads that fragment and that any loss of effectiveness sustained by going with a bonded bullet or solid copper bullet is inconsequential compared to the benefits of utilizing such a load.
Thats what Im getting over here. I always though 75gr TAP was THE load for HD(un-obstructed targets). However, Im reading that it doesnt always perform like the gel tests ive seen?
For non-barrier confrontations, is 75gr tap/77nosler still the best or is the 50gr tsx, gold dots, and mk 318 better and save the heavy stuff for long range?
with mk318 around $10 box now, im definitely grabbing some soon. 62gr 5.56 otmrp is 318 right?
This is why I like MK318 SOST.
You get your violent fragmentation and your penetration AND I have noted that barrier or not, it continues in the direction it was pointed initially. It does not yaw/deviate that I could determine.
I spoke with a guy that liked the SOST round so much/how it worked for him in combat, that when he came home, he bought a good supply of them. He was in a unit that was issued MK318, and saw the round as well as others used for effect. His experience, also backed by gel and lab tests, corroborates my opinion that the round is about the best "compromise" you can achieve in this caliber.
vicious_cb
12-06-11, 07:38
As stated by Doc, the SOST and TAP rounds have similar wound profiles in regards to fragmentation except the solid copper shank tends to over penetrate the target. Food for thought when choosing Mk318 for HD.
As stated by Doc, the SOST and TAP rounds have similar wound profiles in regards to fragmentation except the solid copper shank tends to over penetrate the target. Food for thought when choosing Mk318 for HD.
This is a good point to consider for HD or LE use of the mk318 round. The higher level of penetration isn't a problem in military use but could be a major issue for civilian defensive or police use. I'm still convinced that a bonded round into 62-64gr range or the 50gr TSX is the way to go for those applications.
to the OP, look at the 50grain tsx-x loads, they offer outstanding wound channels and are solid copper.
It seems to me that solid copper rifle bullets, like those offered by Barnes, and bonded lead-core rifle bullets don't produce the same amount of wound trauma as conventional unbonded lead-core expanding rifle bullets, ?
It seems to me this is a function of how rapidly and how wide the bullet expands. Barnes have been known to be a hard bullet, expanding more slowly than some lead core bullets. The same is likely true of bonded core bullets because persons purchasing them expect deeper penetration which can be achieved through slower expansion.
It seems to me this is a function of how rapidly and how wide the bullet expands. Barnes have been known to be a hard bullet, expanding more slowly than some lead core bullets. The same is likely true of bonded core bullets because persons purchasing them expect deeper penetration which can be achieved through slower expansion.
Data? I have seen the opposite.
How is it physically possible that a bullet will "delay" expansion? If, at impact (highest hydraulic forces) it does not expand, how is it going to expand LATER when the forces acting upon it are even less? Once it begins to expand, it's going to do so faster and faster as the surface area increases exponentially as does the force on the bullet material in kind.
All this "controlled expansion" stuff, I do not understand.
This is a good point to consider for HD or LE use of the mk318 round. The higher level of penetration isn't a problem in military use but could be a major issue for civilian defensive or police use. I'm still convinced that a bonded round into 62-64gr range or the 50gr TSX is the way to go for those applications.
5.56 mm Fed Mk318 Mod0 62 gr OTM (T556TNB1) fired from 16" 1/7 barrel AR15 at an ave MV of 2928 fps; 3 shot ave noted below:
BG: Pen = 17.3", NL = 1 cm, Max TC 11 cm @ 8 cm pen/extending to 17 cm, RD = 0.26", RL = 0.41", RW = 34.2 gr
AG: Pen = 18.1", NL = 0 cm, Max TC 7.5 cm @ 7 cm pen/extending to 15 cm, RD = 0.30", RL = 0.35", RW = 33.0 gr
5.56 mm Win 64 gr bonded FBI JSP (Q3313/RA556B) fired from 16" 1/7 barrel AR15 no MV recorded due to damaged chronograph; 3 shot ave noted below:
BG: Pen = 17.1", NL = 1 cm, max TC 10 cm @ 10 cm pen/extending to 19 cm, RD = 0.46", RL = 0.38", RW = 59.6 gr
AG: Pen = 13.6", NL = 0 cm, max TC 7 cm @ 8 cm pen/extending to 15 cm, RD = 0.35", RL = 0.37", RW = 34.6 gr
Because 0.2" more penetration is 0.2" too much? I'll stick with my SOST. Not that the other is a bad choice, but over-penetration seems to be a very weak justification for it, over SOST.
The 50gr TSX is a little better...I'm still not sweating 2.6" penetration in gel as the end of the world...about an inch less than the calibration BB used in gel tests.
Below is some data from the new BH 5.56 mm 50 gr TSX load.
5 shot averages fired at 3 meters from 14.5" M4 w/ave MV of 3012 fps:
BG: pen=14.7" RD=0.47" RW=49.9gr
Steel: pen=19.4" RD=0.22" RW=49.6gr
Wall: pen=16.7" RD=0.46" RW=49.9gr
Auto Glass: pen=17.0" RD=0.36" RW=43.4gr
FYI, the 357SIG penetrates over 17" in gel. Noone in LE has experienced it over-penetrating people, though. In fact, it seems to remain in the body/clothing most of the time. Gel is not people.
vicious_cb
12-06-11, 11:56
Data? I have seen the opposite.
How is it physically possible that a bullet will "delay" expansion? If, at impact (highest hydraulic forces) it does not expand, how is it going to expand LATER when the forces acting upon it are even less? Once it begins to expand, it's going to do so faster and faster as the surface area increases exponentially as does the force on the bullet material in kind.
All this "controlled expansion" stuff, I do not understand.
One way to do it is to use a polymer plug in the hollow point cavity, depending on the characteristics of the plug material you can alter how quickly the bullet expands. This is what hornady does in their FTX bullets. Don't know if this would work with rifle bullets though.
One way to do it is to use a polymer plug in the hollow point cavity, depending on the characteristics of the plug material you can alter how quickly the bullet expands. This is what hornady does in their FTX bullets. Don't know if this would work with rifle bullets though.
Not what Hornady claims.
FTX® bullets provide the devastating terminal performance you have come to expect from Hornady®. Upon impact, the soft tip compresses into the bullet, initiating immediate expansion that transfers energy to the target for quick kills.
http://www.hornady.com/store/FTX-newbullets
Not what Hornady claims.
FTX® bullets provide the devastating terminal performance you have come to expect from Hornady®. Upon impact, the soft tip compresses into the bullet, initiating immediate expansion that transfers energy to the target for quick kills.
http://www.hornady.com/store/FTX-newbullets
looks like a bonded ballistic tip, fast expansion, but it stays together. Great for hunting, but it would probably be destroyed by penetrating barriers... need to test it to know for sure though.
looks like a bonded ballistic tip, fast expansion, but it stays together. Great for hunting, but it would probably be destroyed by penetrating barriers... need to test it to know for sure though.
It is not bonded, the "InterLock" you see referenced is just the contour of the inside of the jacket designed to hold the core in place.
I wish companies would dispense with the cute terms and just tell us what things really are without having to read the fine print, but that just doesn't sell.
so it doesnt "keep it together" it locks it from spinning inside the jacket? Thats some horrible terminology.
so it doesnt "keep it together" it locks it from spinning inside the jacket? Thats some horrible terminology.
Well, from the data we have from most of Hornady's stuff...and hearing from Hornady themselves that they find it "impossible" to make a pistol projectile that can adequately defeat barriers...one does have to ask of Hornady: "wtf is wrong with you?"
Thats what Im getting over here. I always though 75gr TAP was THE load for HD(un-obstructed targets). However, Im reading that it doesnt always perform like the gel tests ive seen?
For non-barrier confrontations, is 75gr tap/77nosler still the best or is the 50gr tsx, gold dots, and mk 318 better and save the heavy stuff for long range?
It's not that 75gr OTMs don't perform as advertised. I think Doctor Roberts is now saying that barrier blind performance is more important than originally thought - even for the civilian - that going to a "one bullet that does it all" is the best idea.
5.56 mm Fed Mk318 Mod0 62 gr OTM (T556TNB1) fired from 16" 1/7 barrel AR15 at an ave MV of 2928 fps; 3 shot ave noted below:
BG: Pen = 17.3", NL = 1 cm, Max TC 11 cm @ 8 cm pen/extending to 17 cm, RD = 0.26", RL = 0.41", RW = 34.2 gr
AG: Pen = 18.1", NL = 0 cm, Max TC 7.5 cm @ 7 cm pen/extending to 15 cm, RD = 0.30", RL = 0.35", RW = 33.0 gr
5.56 mm Win 64 gr bonded FBI JSP (Q3313/RA556B) fired from 16" 1/7 barrel AR15 no MV recorded due to damaged chronograph; 3 shot ave noted below:
BG: Pen = 17.1", NL = 1 cm, max TC 10 cm @ 10 cm pen/extending to 19 cm, RD = 0.46", RL = 0.38", RW = 59.6 gr
AG: Pen = 13.6", NL = 0 cm, max TC 7 cm @ 8 cm pen/extending to 15 cm, RD = 0.35", RL = 0.37", RW = 34.6 gr
Because 0.2" more penetration is 0.2" too much? I'll stick with my SOST. Not that the other is a bad choice, but over-penetration seems to be a very weak justification for it, over SOST.
The 50gr TSX is a little better...I'm still not sweating 2.6" penetration in gel as the end of the world...about an inch less than the calibration BB used in gel tests.
Below is some data from the new BH 5.56 mm 50 gr TSX load.
5 shot averages fired at 3 meters from 14.5" M4 w/ave MV of 3012 fps:
BG: pen=14.7" RD=0.47" RW=49.9gr
Steel: pen=19.4" RD=0.22" RW=49.6gr
Wall: pen=16.7" RD=0.46" RW=49.9gr
Auto Glass: pen=17.0" RD=0.36" RW=43.4gr
FYI, the 357SIG penetrates over 17" in gel. Noone in LE has experienced it over-penetrating people, though. In fact, it seems to remain in the body/clothing most of the time. Gel is not people.
It was my understanding that the shank of the SOST round penetrated well beyond 18". If that is not the case and it only penetrates 17.3" as the data you posted shows then it certainly isn't the issue I thought it was.
It's not that 75gr OTMs don't perform as advertised. I think Doctor Roberts is now saying that barrier blind performance is more important than originally thought - even for the civilian - that going to a "one bullet that does it all" is the best idea.
Well, that's what I got and tried to restate:
It's not that you have some delta of added effectiveness with one fragmentation over a bonded bullet, theoretically; it's that a bonded/solid copper can effectively handle a vast majority of situations without failure, making them more effective overall, and giving you a greater advantage in the real world.
Fragmenting bullets may in fact cause more damage in certain circumstances, which might make them a better choice for those circumstances. But, if you are in a general-effect circumstance where you have no way to predict WHAT characteristics you're going to need, going with a bullet that's better overall at a wider range of circumstances is more prudent.
so it doesnt "keep it together" it locks it from spinning inside the jacket? Thats some horrible terminology.
No, the "interlock" is to keep the jacket and the core together.
Ref bonded and whatever bullets; all that expand do so almost instantly, within the first inch or two of gelatin, there is no delay at all. Penetration depths then rely of bullet weight, how wide it expands (more expansion=more parachute effect), and how much it fragments and loses mass.
No, the "interlock" is to keep the jacket and the core together.
Ref bonded and whatever bullets; all that expand do so almost instantly, within the first inch or two of gelatin, there is no delay at all. Penetration depths then rely of bullet weight, how wide it expands (more expansion=more parachute effect), and how much it fragments and loses mass.
and input velocity.
and input velocity.
Yep, can't forget that...
It's not that 75gr OTMs don't perform as advertised. I think Doctor Roberts is now saying that barrier blind performance is more important than originally thought - even for the civilian - that going to a "one bullet that does it all" is the best idea.
The role of the civilian in a gun-fight has not changed (survival/defense of life/limb/loved one's.)
Is it that barrier blind performance is being realized as more important, or is it that barrier blind performance is being realized as more possible?
It was my understanding that the shank of the SOST round penetrated well beyond 18". If that is not the case and it only penetrates 17.3" as the data you posted shows then it certainly isn't the issue I thought it was.
The data I posted is the only data that I could find from a lab on the projectile--MD Robert's data.
No, the "interlock" is to keep the jacket and the core together.
Ref bonded and whatever bullets; all that expand do so almost instantly, within the first inch or two of gelatin, there is no delay at all. Penetration depths then rely of bullet weight, how wide it expands (more expansion=more parachute effect), and how much it fragments and loses mass.
yeah, from what I understand it's basically a "ring" protruding from the jacket into the core to keep it from slipping. :rolleyes:
"or is it that barrier blind performance is being realized as more possible? "
Ding, ding...we have a winner!!!
The data I posted is the only data that I could find from a lab on the projectile--MD Robert's data.
I still have two questions about the Mk318. First, as was mentioned earlier in this thread, fragmentation tends to be less consistent than expansion. The Mk318 shank should essentially be a .22 cal wadcutter once the front of the bullet has fragmented so I'd like to compare the gel shot side by side. Does the Mk318 cause good damage shallow but leave a small wound track toward the end of its penetration when compared to an expanding bullet?
Also, does the Mk318 have any issues with shots through arms and the like? If it fragments in the arm I would think the only thing to reach the body and be effective would be the shank.
I'm still gonna stick with my expanding bonded bullets and TSX's for now, but if the price of surplus Mk318 comes down in the future it very easily could become my bulk ammo reserve load in place of M193 or M855. It will have to come down a ways to do that, though, since I was able to get bonded Federal ammo for .50/round this year.
Either way I'm very glad the troops have something better, which was the whole point behind the Mk318 in the first place.
Leatherneck556
12-07-11, 08:44
A couple thoughts and questions:
1. I've posted this before - and I'm sure that somebody smarter than I am will point out why I'm wrong - but I can't shake the logic that WS6 puts forth as to why he likes the Mk318 and his general purpose round. If nearly half the bullet's mass fragments in the first several inches of penetration, then wouldn't you get that synergistic effect described in the last paragraph of Doc's linked sticky and also get the ensured deep penetration through a variety of mediums by the copper shank? I know that I've been told "compare the recovered diameter of Mk318 with the RD of bonded rounds and you'll see there's no comparison." It's true that the RD is substantially smaller, but the bonded rounds also have substantially less fragmentation. In unobstructed shots, wouldn't it be 6 one way and a half dozen the other? Both penetrate to similar depths, and one expands whereas the other fragments. I realize that through hard barriers (like auto glass), the Mk318 is going to go through most of its fragmentation in the barrier vice the body of its final target and therefore produce a smaller permanent cavity. But for unobstructed shots, wouldn't a partially fragmenting round like Mk318 or Nosler Partition produce wound tracts with more (or at least an equivalent level of) destroyed tissue as bonded/expanding projectiles?
The cost, availability, and military spec quality control features of Mk318 also make it very desirable (5.56 pressures, crimped & sealed primers, sealed case neck, same trajectory as M855 so it matches many common ACOG BDC's, etc).
2. In reference to overpenetration being a concern in Home Defense/CQB, I don't look at it so much as a concern with penetrating through your target, but rather penetration off of a missed shot. Obviously we always need to "be aware of our target, its foreground, and its background", but sometimes you still must take a shot and sometimes you miss. I would be interested to see a comparison of penetration of different rounds (Hornady 75gr TAP, 50gr TSX, and Mk318) through commonly encountered barriers in the home, such as drywall, furniture, metal & wooden doors, and non-automobile glass. Maybe that doesn't need to be tested - maybe that's already been done and somebody can tell me that all of those various rounds will penetrate about the same in ballistic gel after passing through those various barriers or that it isn't the case. Regardless, it's those missed shots that give me pause to worry about overpenetration. If I'm shooting at a badguy behind a windshield, then the notion that the Mk318 round will go a little over 18" doesn't bother me at all. It's the concern that if I miss my target in a HD scenario, the round will continue to be lethal as it enters an adjacent [occupied] apartment or a family member's room.
A couple thoughts and questions:
1. I've posted this before - and I'm sure that somebody smarter than I am will point out why I'm wrong - but I can't shake the logic that WS6 puts forth as to why he likes the Mk318 and his general purpose round. If nearly half the bullet's mass fragments in the first several inches of penetration, then wouldn't you get that synergistic effect described in the last paragraph of Doc's linked sticky and also get the ensured deep penetration through a variety of mediums by the copper shank? I know that I've been told "compare the recovered diameter of Mk318 with the RD of bonded rounds and you'll see there's no comparison." It's true that the RD is substantially smaller, but the bonded rounds also have substantially less fragmentation. In unobstructed shots, wouldn't it be 6 one way and a half dozen the other? Both penetrate to similar depths, and one expands whereas the other fragments. I realize that through hard barriers (like auto glass), the Mk318 is going to go through most of its fragmentation in the barrier vice the body of its final target and therefore produce a smaller permanent cavity. But for unobstructed shots, wouldn't a partially fragmenting round like Mk318 or Nosler Partition produce wound tracts with more (or at least an equivalent level of) destroyed tissue as bonded/expanding projectiles?
The cost, availability, and military spec quality control features of Mk318 also make it very desirable (5.56 pressures, crimped & sealed primers, sealed case neck, same trajectory as M855 so it matches many common ACOG BDC's, etc).
2. In reference to overpenetration being a concern in Home Defense/CQB, I don't look at it so much as a concern with penetrating through your target, but rather penetration off of a missed shot. Obviously we always need to "be aware of our target, its foreground, and its background", but sometimes you still must take a shot and sometimes you miss. I would be interested to see a comparison of penetration of different rounds (Hornady 75gr TAP, 50gr TSX, and Mk318) through commonly encountered barriers in the home, such as drywall, furniture, metal & wooden doors, and non-automobile glass. Maybe that doesn't need to be tested - maybe that's already been done and somebody can tell me that all of those various rounds will penetrate about the same in ballistic gel after passing through those various barriers or that it isn't the case. Regardless, it's those missed shots that give me pause to worry about overpenetration. If I'm shooting at a badguy behind a windshield, then the notion that the Mk318 round will go a little over 18" doesn't bother me at all. It's the concern that if I miss my target in a HD scenario, the round will continue to be lethal as it enters an adjacent [occupied] apartment or a family member's room.
Any round that will be effective on a human target will pass through several layers of drywall, the most common barrier in a home. The Box Of Truth is a good spot to look up info on that but I don't think they've tested Mk318 (unless it has been put up since I was last there). Even a .22LR will pass through walls.
I would suspect a Mk318 shank would penetrate more walls since the shank is of smaller diameter than an expanded bonded bullet or TSX but I haven't seen testing to prove that.
Ultimately, you need to plan ahead when deciding how to deal with an intruder at home as much as possible to minimize the chance of having to take a shot where the background is a wall to your kid's room. I've also taught my kids that if the alarm goes off or the dogs go nuts (a home alarm and a couple large dogs are great investments) they are to go to a specific place in their rooms and get low. These spots are behind furniture and in the least likely places to expose them to any cross fire.
I use bonded 62gr Federal loads for Home Defense, FWIW. I'm stuck with 55gr TRU JSP at work, which I'm trying to change. Ridiculous that I would have to use a less effective round working as an LEO when I'm far more likely to get into a shooting, especially involving a barrier like a windshield...
I underlined the key point
While the Mk318 is a great round for military personnel, there are a lot of better options for LE and civilians, as listed in the second paragraph here: https://www.m4carbine.net/showthread.php?t=19881
Folks,
Are you willing to fire your duty/CCW handgun indoors?
If you are, then why are you concerned about properly engineered blind to barrier 5.56 mm loads, since ALL of the current effective barrier blind ammunition penetrates NO more than service caliber handgun ammunition in the event of a miss. For that matter, the recommended 7.62 x 51mm loads for 16" rifle use, like the Rem 150 gr CLUB, penetrate the same depth as handgun rounds...
The better bonded loads like TBBC, are definitely MORE effective than the TSX style all copper bullets, as they expand better, retain more mass, and offer a larger surface area, especially through intermediate barriers.
The current generation of LE barrier blind loads like 5.56 mm Federal 62 gr Trophy Bonded Bear Claw (TBBC) bonded JSP (XM556FBIT3) and 5.56 mm Winchester 64 gr solid base bonded JSP (Q3313/RA556B) developed for the FBI, are at 5.56 mm pressures using appropriate crimped & sealed primers, sealed case neck, same trajectory as M855 so it matches many common ACOG BDC's, etc... The new Black Hills 5.56 mm 50 gr TSX loading is another 5.56 mm offering which offers many of these same features--it matches closely with 5.56 mm 55 gr M193 practice ammo...
If you don't wish to believe the above, contact the FBI BRF and get their take on this issue.
Folks,
Are you willing to fire your duty/CCW handgun indoors?
If you are, then why are you concerned about properly engineered blind to barrier 5.56 mm loads, since ALL of the current effective barrier blind ammunition penetrates NO more than service caliber handgun ammunition in the event of a miss. For that matter, the recommended 7.62 x 51mm loads for 16" rifle use, like the Rem 150 gr CLUB, penetrate the same depth as handgun rounds...
The better bonded loads like TBBC, are definitely MORE effective than the TSX style all copper bullets, as they expand better, retain more mass, and offer a larger surface area, especially through intermediate barriers.
The current generation of LE barrier blind loads like 5.56 mm Federal 62 gr Trophy Bonded Bear Claw (TBBC) bonded JSP (XM556FBIT3) and 5.56 mm Winchester 64 gr solid base bonded JSP (Q3313/RA556B) developed for the FBI, are at 5.56 mm pressures using appropriate crimped & sealed primers, sealed case neck, same trajectory as M855 so it matches many common ACOG BDC's, etc... The new Black Hills 5.56 mm 50 gr TSX loading is another 5.56 mm offering which offers many of these same features--it matches closely with 5.56 mm 55 gr M193 practice ammo...
If you don't wish to believe the above, contact the FBI BRF and get their take on this issue.
Side note: unfortunately, while the TBBC bullets are great, i can't seem to find a single retailer that has it. :confused::angry::blink:
QuietShootr
12-07-11, 13:57
Folks,
Are you willing to fire your duty/CCW handgun indoors?
If you are, then why are you concerned about properly engineered blind to barrier 5.56 mm loads, since ALL of the current effective barrier blind ammunition penetrates NO more than service caliber handgun ammunition in the event of a miss. For that matter, the recommended 7.62 x 51mm loads for 16" rifle use, like the Rem 150 gr CLUB, penetrate the same depth as handgun rounds...
The better bonded loads like TBBC, are definitely MORE effective than the TSX style all copper bullets, as they expand better, retain more mass, and offer a larger surface area, especially through intermediate barriers.
The current generation of LE barrier blind loads like 5.56 mm Federal
If you don't wish to believe the above, contact the FBI BRF and get their take on this issue.
What's this?
Leatherneck556
12-07-11, 14:06
Altair, I couldn't agree more with your assessment of home defense. If your only home defense plan is your weapon... well then you don't actually have a home defense plan. It's a layered system and I completely agree with the notion that you need to arrange your living space in a way that minimizes the chances you'll have to shoot in a family member's direction.
Todd, I've seen that particular post before and I understand that expanding rounds are the overall better choice. I understand that the recovered diameter of a bonded or solid copper projectile will be bigger, but those expanding rounds also don't produce substantial fragmentation earlier in the wound tract, and that fragmentation is an apparently powerful wounding mechanism itself - as some of Doc's posts have indicated. I'm only talking about unobstructed shots. I know that in shots through barriers, the partial fragmentation will occur before it actually hits the intended target, whereas expanding rounds will still expand to a large diameter regardless of barriers. It is my understanding that because of this better barrier performance, the expanding rounds are the all-around better performer. What I'm trying to understand - and what I feel like I can't find an answer for - concerns unobstructed shots: In unobstructed shots, does the fragmentation produced by rounds like SOST and Partition not produce a wound cavity on par with expanding bonded/solid copper rounds?
As for overpenetration concerns, I was really trying to bring up the subject of non barrier-blind rounds like TAP. I understand that service handgun calibers will often get deeper penetration through drywall than 5.56 rounds will, but I was thinking in terms of avoiding that problem through ammunition selection. But it's like Altair said - ammunition selection cannot be the only mitigating factor you rely on in avoiding overpenetration. Setting up your "engagement area" such that you have a clear background is even more important.
It's certainly not that I don't believe that XM556FBIT3 is the all-around best 5.56 loading out there that one can pick, it's just that I literally cannot find the stuff. I mean, are the FBI loads available right now? And if/when they are available, doesn't that stuff cost darn near $2.00 per round? 50gr TSX is also quite high. If there is a reasonably priced supply of it out there, then I wouldn't worry about any of this stuff. But as it stands, availability and cost make this prohibitive. T556TNB1, on the other hand, is relatively cheap and plentiful, and has those other desirable characteristics (5.56, crimped, sealed, etc).
Leatherneck556
12-07-11, 14:37
I think that I'm starting to figure this out now.
I'm still curious about my question as to how wound cavities produced by partially fragmenting rounds compare to those produced by expanding rounds in unobstructed shots.
But I'm starting to get a better idea about using barrier blind ammo in the home defense role. Looking back at the numbers in Doc's tests, I feel like an expanding barrier blind round like TBBC, Gold Dot, TSX, or Fusion would be less likely to overpenetrate than something like SOST.
Where cost and availability become a factor, it would make sense to keep maybe one magazine of something like 55gr 5.56 Gold Dots, BH 50gr TSX, one of the FBI loads, or a .223 Fusion/Gold Dot round as your go-to home defense load, and the rest of your mags loaded with the cheaper Mk318 round. Zero the gun with Mk318, but make the primary HD round one of the expanding ones - the point of impact difference will be negligible out to 100 yards, and you're not likely to encounter a home defense scenario where you're shooting much farther than that anyway. If you do need to shoot farther than that (ie: I live in a rural area on a big farm and I've had to approach suspected trouble from a distance before), then you could just run your bulk defensive round (like SOST) as your primary because the distance involved and safer backdrop negate some of the concerns of fighting in the home.
Does that make sense, or am I over-complicating things? I'm seriously bored on this sea-based deployment and I spend WAY too much time overthinking things that I don't really need to worry about.
QuietShootr--CLUB = http://www.remington.com/products/ammunition/centerfire/premier-core-lokt/premier-core-lokt-ultra-bonded.aspx; see bottom of page here: https://www.m4carbine.net/showthread.php?t=19878
What's this?
I believe it's the Remington 150 gr Core-Lokt Ultra Bond JSP
eta...guess the good Doc beat me to it, better him than me anyway:)
Any of the rifle loads mentioned (https://www.m4carbine.net/showthread.php?t=19881) is going to work better than a handgun projectile at stopping a lethal threat. Everything has advantages and disadvantages. Don't get too worked up over minor points of minutia in ammo selection. Keep in mind the bigger picture... As stated before, I would much rather go into battle with a guy who practices 15,000 rounds a year using generic 55 gr FMJ out of his old M16A1 or the gal who shoots a similar amount of 75 gr OTM from her pink AR15 than with any person that has the latest state-of-the-art ammo and rifle, but only shoots 500 rounds a year.
Is fragmentation nice? Sure, especially if you are in an organization that prohibits expanding projectiles. For LE and other individuals not restricted by the Hague convention, because of their good terminal performance across a wide spectrum of potential engagement scenarios, the bonded barrier blind projectiles have moved ahead of the fragmenting OTM loads we previously recommended, as the best general purpose loads available.
All of my loaded 30 rd mags are currently holding bonded barrier blind projectiles. I do keep a couple of old school 20 rd mags loaded with 75/77 OTM kicking around as well, mainly because I have a lot of still in inventory and it remains very accurate and effective on unobstructed shots. But it is no longer my first choice for a GP load.
"or is it that barrier blind performance is being realized as more possible? "
Ding, ding...we have a winner!!!
I think the velocity dependence of the fragmentation wound mechanism can't be overstated for those using SBRs and/or those stuck with .223 capable uppers. Start limiting muzzle velocity and the range envelope where fragmentation is likely starts to diminish. Throw out a case where all a department or individual has are .223 entry length carbines and the 50gr TSX or 62/64gr JSP offerings are better almost across the board.
Good shot placement or really bad shot placement makes this entire discussion moot/academic, but anybody who has taken the time to read Doc's information and understood it at least understands that 55gr FMJ isn't the pinnacle of ballistic efficiency, and hopefully grasps that a $0.29 component limiting the performance of a $1000+ home defense tool is silly.
Submariner
12-08-11, 08:36
All of my loaded 30 rd mags are currently holding bonded barrier blind projectiles. I do keep a couple of old school 20 rd mags loaded with 75/77 OTM kicking around as well, mainly because I have a lot of still in inventory and it remains very accurate and effective on unobstructed shots. But it is no longer my first choice for a GP load.
What are you doing with your existing stocks of 75/77 OTM? Very expensive training ammo?
For one thing, it is great for shooting matches. In addition, if an LE officer has to make an open air shot at an active shooter at longer ranges, for example at an airport, park, mall, school, or rural area, OTM is a viable option.
For one thing, it is great for shooting matches. In addition, if an LE officer has to make an open air shot at an active shooter at longer ranges, for example at an airport, park, mall, school, or rural area, OTM is a viable option.
Let's say one wanted to do just this. Would you suggest a good zero with the OTM to be able to make long range hits, and used the barrier blind stuff at closer range for general purposes/shooting through stuff?
Yes--that works pretty well and what was done here by many agencies who used to carry both 75 gr OTM and 62 gr TBBC. Alternatively, just use the OTM in a match rifle and not worry about it...
a $0.29 component limiting the performance of a $1000+ home defense tool is silly.
Very well said.
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