View Full Version : Barrier-blind 5.56 loads: negating the strengths of the carbine?*
The recent thread the discussing the ballistic advantage of modern 5.56 loadings compared to loads such as M193 left me with several questions regarding the terminal ballistics of the more advanced barrier blind loadings that are currently available.
I understand that controlled expansion rounds have exhibited better performance when engaging suspects/enemy combatants through intermediate barriers. Additionally, I understand that controlled expansion is a more reliable wounding mechanism compared to fragmentation. However, after a lot of research on the topic, I am left with the following questions:
1. Are the temporary cavitation effects from barrier blind 5.56 loadings significant enough to cause an enhanced degree of wound trauma/complexity without the aid of fragments to cut any of the tissue temporarily strectched? I realize that wounding effects caused by the temporary cavities created by non-expanding/non-fragmenting FMJ rifle rounds is marginal at best (i.e. 7.62x39)
2. If the temporary cavitation created by barrier blind 5.56 loadings do NOT substancially contribute to the wounding characteristics of the projectile, do barrier blind loadings actually reduce the potential effectiveness of the 5.56 carbine platform at the expense of reliable (potentially marginal) performance? In contrast to yawing/fragmenting ammunition that potentially creates substancial damage to tissue surrounding the permanant wound cavity, it would appear that barrier blind loadings rely on a permanent wound cavity that is enlarged by controlled expansion of the projectile.
3. Tests referenced on this forum have indicated that the recovered diameter of most barrier blind loads does not generally exceed .50 in most instances. However, many reputable 9mm hollowpoint loadings regularly have recovered diamters exceeding .60. This difference is even more substancial when comparing .40 S&W and .45 ACP duty ammunition.
If relying on a rifle loading that relies mostly on a permanent cavity as its primary wounding mechanism, does the 5.56 truly offer a ballistic advantage over a handgun projectile that actually creates a larger permanent wound cavity? Note I am referring purely to terminal ballistic factors...the carbine has advantages in external ballistics, i.e. range/accuracy/etc. that obviously outclass the handgun.
In closing...those that recommend barrier blind ammunition: do you view this as a compromise load of sorts, sacrificing some of the potentially devastating fragmentation effects for the sake of barrier penetration and reliable expansion? I understand that I could be way off in my asssumptions regarding the wounding mechanisms of barrier blind ammunition, and would appreciate any information from those with knowledge of the topic.
In closing...those that recommend barrier blind ammunition: do you view this as a compromise load of sorts, sacrificing some of the potentially devastating fragmentation effects for the sake of barrier penetration and reliable expansion? I understand that I could be way off in my asssumptions regarding the wounding mechanisms of barrier blind ammunition, and would appreciate any information from those with knowledge of the topic.
Any ammunition choice is going to be a compromise. If you know you will only engage naked skinny subjects not using cover, you might choose a different projectile, than if you may encounter obese subjects, wearing heavy clothing, who may hide behind vehicles or interior walls.
Any ammunition choice is going to be a compromise. If you know you will only engage naked skinny subjects not using cover, you might choose a different projectile, than if you may encounter obese subjects, wearing heavy clothing, who may hide behind vehicles or interior walls.
Understood. Would you acknowledge then that 5.56 barrier blind loadings offer no terminal ballistic superiority to the permanent wound cavities created by handgun calibers in your opinion? Or do you believe that barrier blind loadings still offer a significant wounding advantage?
Good barrier blind 5.56mm/.223 loads damage more tissue and are far more likely to incapacitate a dangerous aggressor than service caliber handgun projectiles.
3. Tests referenced on this forum have indicated that the recovered diameter of most barrier blind loads does not generally exceed .50 in most instances. However, many reputable 9mm hollowpoint loadings regularly have recovered diamters exceeding .60. This difference is even more substancial when comparing .40 S&W and .45 ACP duty ammunition.
What is the scientifically determined difference in effectiveness between a .50 and .60 diameter projectile? (a percentage or other unit of measurement)
I don't know and neither does anyone else.
Would you acknowledge then that 5.56 barrier blind loadings offer no terminal ballistic superiority to the permanent wound cavities created by handgun calibers in your opinion?
You need to look at the total amount of tissue that each can destroy.
This sticky may be a good place to start.
Basic Wound Ballistic Terminal Performance Facts https://www.m4carbine.net/showthread.php?t=34714
"Unlike rifle bullets, handgun bullets, regardless of whether they are fired from pistols or SMG’s, generally only disrupt tissue by the crush mechanism. In addition, temporary cavitation from most handgun bullets does not reliably damage tissue and is not usually a significant mechanism of wounding."
I had this same question myself, and attempted to answer it through a literature search. My understanding is as follows:
Expanding barrier blind 5.56 bullets and handgun bullets both bore out a permanent crush cavity analogous to the expanded diameter of the projectile. As you have already pointed out, the expanded diameter of 5.56 barrier blind rounds is smaller than quality 9mm hollow points. The added advantage of the 5.56 barrier blind rounds is the temporary cavitation, which is insignificant in handgun bullets.
Elastic tissues such as muscle and lung are not permanently damaged by temporary cavitation. Inelastic and fluid filled structures such as the brain, heart, liver, spleen, kidneys, and (full) bladder, however, are devastated by this phenomenon. Temporary cavitation can also injure the spinal cord either temporarily or permanently, thereby immediately ending hostilities.
From what I understand (SME's please correct me if I am mistaken) barrier blind bullets passing within temporary cavity range of the above structures will be just as effective as a fragmenting round that causes permanent tearing within the temporary cavity. In either case, the organ will be shredded and massive hemorrhage will occur.
I question, however, whether you might get inferior performance with certain shot placements. Although the brain, heart, spinal cord, liver, spleen, kidneys etc. are all subject to the effects of temporary cavitation, there are areas of the body that do not contain vulnerable structures. Consider these hypotheticals:
Imagine a bullet that passes through the outer margin of the lung. Because lung tissue is unaffected by temporary cavitation, the barrier blind round might only create a .45" wound track and leave the body. A fragmenting round, however, could create a sphere of tissue destruction several inches in diameter. In the process, this could destroy enough pulmonary vasculature to bring about a quick cessation of hostilities through rapid blood loss.
Next, imagine a bullet that tracks through the thigh a couple inches from the femur and femoral vessels. From what I understand, temporary cavitation does not destroy bone (SME's please correct me if I am wrong). Therefore, a barrier blind round might go through the leg leaving a .45" wound track. The fragmenting round, however, might destroy the femur and femoral vessels, thereby ceasing hostilities.
If my hypotheticals are correct, I question whether something like mk 318 with a balance between fragmentation and a penetrating core might be a logical balance. In unobstructed shots, it might yield better results with hits to the limbs, pelvis, outer thorax, etc. while at the same time being able to cause a(n albeit smaller) penetrating wound and temporary cavity in targets shielded by boundaries.
I welcome any comments or criticism of the above, as I would like to know if my conclusions are incorrect.
The problem with classic 7.62x39 ammunition is that it yaws late, and therefore creates its large temporary cavity late. In many instances, this will not occur until the bullet has already left the bad guy. Without the yaw or temporary cavity, you will essentially be left with a wound similar to a FMJ pistol bullet.
I had this same question myself, and attempted to answer it through a literature search. My understanding is as follows:
Expanding barrier blind 5.56 bullets and handgun bullets both bore out a permanent crush cavity analogous to the expanded diameter of the projectile. As you have already pointed out, the expanded diameter of 5.56 barrier blind rounds is smaller than quality 9mm hollow points. The added advantage of the 5.56 barrier blind rounds is the temporary cavitation, which is insignificant in handgun bullets.
Elastic tissues such as muscle and lung are not permanently damaged by temporary cavitation. Inelastic and fluid filled structures such as the brain, heart, liver, spleen, kidneys, and (full) bladder, however, are devastated by this phenomenon. Temporary cavitation can also injure the spinal cord either temporarily or permanently, thereby immediately ending hostilities.
From what I understand (SME's please correct me if I am mistaken) barrier blind bullets passing within temporary cavity range of the above structures will be just as effective as a fragmenting round that causes permanent tearing within the temporary cavity. In either case, the organ will be shredded and massive hemorrhage will occur.
I question, however, whether you might get inferior performance with certain shot placements. Although the brain, heart, spinal cord, liver, spleen, kidneys etc. are all subject to the effects of temporary cavitation, there are areas of the body that do not contain vulnerable structures. Consider these hypotheticals:
Imagine a bullet that passes through the outer margin of the lung. Because lung tissue is unaffected by temporary cavitation, the barrier blind round might only create a .45" wound track and leave the body. A fragmenting round, however, could create a sphere of tissue destruction several inches in diameter. In the process, this could destroy enough pulmonary vasculature to bring about a quick cessation of hostilities through rapid blood loss.
Next, imagine a bullet that tracks through the thigh a couple inches from the femur and femoral vessels. From what I understand, temporary cavitation does not destroy bone (SME's please correct me if I am wrong). Therefore, a barrier blind round might go through the leg leaving a .45" wound track. The fragmenting round, however, might destroy the femur and femoral vessels, thereby ceasing hostilities.
If my hypotheticals are correct, I question whether something like mk 318 with a balance between fragmentation and a penetrating core might be a logical balance. In unobstructed shots, it might yield better results with hits to the limbs, pelvis, outer thorax, etc. while at the same time being able to cause a(n albeit smaller) penetrating wound and temporary cavity in targets shielded by boundaries.
I welcome any comments or criticism of the above, as I would like to know if my conclusions are incorrect.
The problem with classic 7.62x39 ammunition is that it yaws late, and therefore creates its large temporary cavity late. In many instances, this will not occur until the bullet has already left the bad guy. Without the yaw or temporary cavity, you will essentially be left with a wound similar to a FMJ pistol bullet.
Yup....wanted to hear some good answers regarding this for a long time. Thanks for posting this.
As Calvin eluded to, I'm in the same boat on my current selection of Mk318, but I'm looking at moving to 50gr TSX.
I'm willing to give up the round performing great at one thing in order to have the following three effects occur with maximum consistency:
Early upset in soft tissue - against a soft target having sufficient deformation and/or fragmentation before exiting
Have sufficient effect on target - large enough temporary or permanent cavity to improve probability of incapacitation
Maintain terminal effects after intermediate barriers - be able to pass through a car door or window without becoming ineffectual
OTM rounds like Mk262 and TAP do the first two very well. M855 and similarly cored rounds do fairly well at maintaining effectiveness through many barriers, but suffer at the first two. Light FMJ like XM193 does very well at the first two provided adequate velocity, but this becomes challenging through SBRs.
Right now I'm waiting to see a good price on the 50gr TSX 5.56 loading from BH or a similar outfit - but I don't feel like I've done poorly using Mk318 civilian loads, I just would prefer a bit longer range out of an SBR and to be rid of the odd accuracy issues some of the civilian lots of Mk318 ammunition have. I'll probably keep using 318 through every rifle with a 62gr BDC, but that will be it.
Leatherneck556
11-21-11, 07:03
I've wondered about this topic myself. I don't doubt that any load - whether expanding or fragmenting - from a rifle is going to have better terminal effectiveness than a pistol round. But I also guess I don't fully understand the subtle nuances of terminal ballistics. I believe that my understanding of the difference between fragmentation and expansion is solid, and that leads me to believe that something like Mk318 would be pretty much an ideal round (barrier blind, early upset, large temporary cavity, fragments but also retains enough mass to get deep penetration albeit at .22" in diameter), but I know that according to Doc this isn't the case.
I don't doubt Doc's recommendations (he's done the research and I haven't), but I still don't really fully understand why some things are the way they are. I've always thought that fragmenting rounds made significantly worse wounds in a soft target than expanding rounds, but I've also seen that the recommendations are for bonded rounds over Mk318 because of their larger expanded diameter. This discrepancy between the two above lines of thought continues to confuse me.
Doc, how reliable is the yawing and fragmentation of a m855 or m193 in wounding as compared to the expansion of a barrier blind, SP or HP? SP and HPs generally expand the majority right? Do m193 and m855 yaw and fragment just as often?
My point here is if the yaw and fragmentation in the FMJs happen, let's say 40% of the time, and the SP and HPs expand 90% of the time then there's a big advantage in the SP and HPs.
sullafelix
11-21-11, 15:00
I had this same question myself, and attempted to answer it through a literature search. My understanding is as follows:
Expanding barrier blind 5.56 bullets and handgun bullets both bore out a permanent crush cavity analogous to the expanded diameter of the projectile. As you have already pointed out, the expanded diameter of 5.56 barrier blind rounds is smaller than quality 9mm hollow points. The added advantage of the 5.56 barrier blind rounds is the temporary cavitation, which is insignificant in handgun bullets.
Elastic tissues such as muscle and lung are not permanently damaged by temporary cavitation. Inelastic and fluid filled structures such as the brain, heart, liver, spleen, kidneys, and (full) bladder, however, are devastated by this phenomenon. Temporary cavitation can also injure the spinal cord either temporarily or permanently, thereby immediately ending hostilities.
From what I understand (SME's please correct me if I am mistaken) barrier blind bullets passing within temporary cavity range of the above structures will be just as effective as a fragmenting round that causes permanent tearing within the temporary cavity. In either case, the organ will be shredded and massive hemorrhage will occur.
I question, however, whether you might get inferior performance with certain shot placements. Although the brain, heart, spinal cord, liver, spleen, kidneys etc. are all subject to the effects of temporary cavitation, there are areas of the body that do not contain vulnerable structures. Consider these hypotheticals:
Imagine a bullet that passes through the outer margin of the lung. Because lung tissue is unaffected by temporary cavitation, the barrier blind round might only create a .45" wound track and leave the body. A fragmenting round, however, could create a sphere of tissue destruction several inches in diameter. In the process, this could destroy enough pulmonary vasculature to bring about a quick cessation of hostilities through rapid blood loss.
Next, imagine a bullet that tracks through the thigh a couple inches from the femur and femoral vessels. From what I understand, temporary cavitation does not destroy bone (SME's please correct me if I am wrong). Therefore, a barrier blind round might go through the leg leaving a .45" wound track. The fragmenting round, however, might destroy the femur and femoral vessels, thereby ceasing hostilities.
If my hypotheticals are correct, I question whether something like mk 318 with a balance between fragmentation and a penetrating core might be a logical balance. In unobstructed shots, it might yield better results with hits to the limbs, pelvis, outer thorax, etc. while at the same time being able to cause a(n albeit smaller) penetrating wound and temporary cavity in targets shielded by boundaries.
I welcome any comments or criticism of the above, as I would like to know if my conclusions are incorrect.
The problem with classic 7.62x39 ammunition is that it yaws late, and therefore creates its large temporary cavity late. In many instances, this will not occur until the bullet has already left the bad guy. Without the yaw or temporary cavity, you will essentially be left with a wound similar to a FMJ pistol bullet.
Coincidentally with your question, Say Uncle posted this link today to a photo showing the results of a thigh wound with 5.56 ball 193 - WARNING GRAPHIC
http://www.timawa.net/forum/index.php?topic=17111.0
Doc, how reliable is the yawing and fragmentation of a m855 or m193 in wounding as compared to the expansion of a barrier blind, SP or HP? SP and HPs generally expand the majority right? Do m193 and m855 yaw and fragment just as often?
My point here is if the yaw and fragmentation in the FMJs happen, let's say 40% of the time, and the SP and HPs expand 90% of the time then there's a big advantage in the SP and HPs.
The fragmentation advantage from M855/M193 is based heavily on whether the projectile is traveling fast enough when it strikes the target. It has been stated in other threads on M4C that the generally accepted fragmentation threshold for M855/M193 is 2700 FPS at impact. If traveling below the threshold it's not going to reliably fragment but still might, and if traveling at or above that speed then it probably will. With M855/M193, fragmentation is a huge damage multiplier for creating a wound, but it is reliant on speed and they aren't good barrier penetrating loads.
Mushrooming and expanding bullets are not reliant on speed thresholds (as much), the ones listed by DocGKR are also good barrier penetrators, and the temporary cavity created by .223 bullets is still enough to tear organs through rapid stretching. For me, that makes the choice a no brainer, I'm going with the intermediate barrier penetrating loads when I don't know what I'm going to encounter. I don't think that you're "losing" much by choosing a mushrooming load over a fragmenting load but if so then I think the margin would be immeasureably small.
The fragmentation advantage from M855/M193 is based heavily on whether the projectile is traveling fast enough when it strikes the target. It has been stated in other threads on M4C that the generally accepted fragmentation threshold for M855/M193 is 2700 FPS at impact. If traveling below the threshold it's not going to reliably fragment but still might, and if traveling at or above that speed then it probably will. With M855/M193, fragmentation is a huge damage multiplier for creating a wound, but it is reliant on speed and they aren't good barrier penetrating loads.
Mushrooming and expanding bullets are not reliant on speed thresholds (as much), the ones listed by DocGKR are also good barrier penetrators, and the temporary cavity created by .223 bullets is still enough to tear organs through rapid stretching. For me, that makes the choice a no brainer, I'm going with the intermediate barrier penetrating loads when I don't know what I'm going to encounter. I don't think that you're "losing" much by choosing a mushrooming load over a fragmenting load but if so then I think the margin would be immeasureably small.
I too would go with the SP or HPs. Here's why I ask for Doc's opinion.
There have been documented instances from Iraq and Afghanistan of the FMJs not upsetting soon enough to cause yaw and fragmentation even at very close distances (less than 50 meters). This leads me to believe that fragmentation does not happen all the time with these rounds.
Coincidentally with your question, Say Uncle posted this link today to a photo showing the results of a thigh wound with 5.56 ball 193 - WARNING GRAPHIC
http://www.timawa.net/forum/index.php?topic=17111.0
Exactly. Would one of the non-fragmenting barrier-blind rounds have created this same wound? My understanding is no, but I would love to hear Doc's thoughts on this thread.
I too would go with the SP or HPs. Here's why I ask for Doc's opinion.
There have been documented instances from Iraq and Afghanistan of the FMJs not upsetting soon enough to cause yaw and fragmentation even at very close distances (less than 50 meters). This leads me to believe that fragmentation does not happen all the time with these rounds.
One of the major issues with the M855/M193 is that they don't fragment consistently after a short neck distance. In other words, due to big spooky math/physics some bullets may fragment after four inches while others don't fragment until they have traversed a greater distance than the thickness of the bad guy's torso. Rounds like Mk318 and 75 grain TAP are better in this regard.
There is no comparison--the recommended barrier blind loads are dramatically more consistent in terminal performance than either M193 or M855, as well as OTM loads in most cases.
I also suggest reading this: https://www.m4carbine.net/showthread.php?t=26905
I'm far more concerned with having a consistent effect when I do manage to achieve good shot placement than having a chance that improves as I'm closer to the target of doing maybe lots of damage.
Within a practical hit-box (CNS augmented with some area in COM where likelihood lung/heart/liver destruction can still lead to rapid incapacitation) 5.56 does a remarkable amount of damage so long as the round upsets soon enough, with temporary cavity tissue damaged being more pronounced if additional rounds pass through the same area.
OTM and JSP rounds do as good or better in terms of this performance as an FMJ will, and certain rounds are more effective at lower velocities - as stated above they just aren't as awesome after passing through certain barriers that one might expect a target to take cover behind.
Fragmentation can be an impressive wound mechanism, but with accurate bullets it becomes dictated by velocity and medium it's striking how soon the projectile will upset enough to fragment, and if the cone of expanding fragments will still be able to do adequate tissue disruption. For an urban entry team or precision rifle an OTM or JSP load can do this extremely well, as mentioned by DocR.
In the bonded loads expansion and penetration aren't necessarily at odds with each other - as long as deformation occurs quickly in soft tissue there will be lots of effects (when compared to a round failing to upset), yet a solid piece of the remaining bullet remains intact and is able to continue penetrating, allowing that same bullet to still be effective if it hits something other than soft tissue on its way to the intended target.
The above image looks like the result of a round striking bone - any high velocity round that does that is going to have a pretty spectacular wound, but counting on hitting skeletal structures is far from ideal.
Pistol calibers simply don't have the energy to do the same kind of damage, and this is especially true with FMJ and certain other loadings where energy is lost to the bullet (or most of it) coming out the other end.
vicious_cb
11-22-11, 05:00
Correct me if I'm wrong but isn't one of the advantages of a fragmenting round is that you increase the probability of striking a vital structure not directly in the path of the main projectile?
I get what Doc is saying about barrier blind JSPs to the best for GP work because you don't know if the threat is going to be behind something but from all the gel shots Ive seen the fragmenting rounds do seem to have a larger wound channel than the bonded JSPs.
I think the big question everyone in this thread wants answered is whether or not we are giving up terminal performance when going from a fragmenting OTM to the bonded JSP in unobstructed shots. In my non-expert opinion Id rather have a fragmenting rounds for unobstructed shots and bonded JSPs for obstructed shots but seeing as how we dont have the luxury of knowing what shots we're going to have to take Id rather go with a barrier blind load.
The way I'm picturing fragmentation occurring without striking hard tissue, the projectile is going to enter, travel a distance before it yaws, then the shear forces on the bullet tear the jacket enough for the bullet to start shedding pieces. If the bullet strikes bone, this is going to happen in a short distance and send many fragments, but if the round passes through soft tissue and some of the fragments strike bone, then there isn't going to be the same magnification of effect.
As far as the main part of the bullet, even in cases like some 77gr SMKs coming apart at the cannelure I wouldn't consider that improving the chances of striking a bone, and at the point where the round is already shearing apart the round isn't going to be extraordinarily more effective if it hits something else - anything still in the fight after one or two of those hits is going to require additional rounds.
I'm overstepping by guessing this, but even fragmenting bullets do significant amounts of damage by having large temporary cavities in addition to the creation of many smaller wound channels, and that the primary improvement of a round impacting with fragmentation that destroys the bullet is that nearly all of that energy is being absorbed by the target in a small timeframe.
Anywhere I can be reasonably assured that I can have the round impact with enough velocity and that needing to penetrate barriers (or maybe mitigate misses - not priority) I'm in the same boat of wanting to run an OTM, and usually in a configuration that maximizes fragmentation range (75gr/77gr).
Correct me if I'm wrong but isn't one of the advantages of a fragmenting round is that you increase the probability of striking a vital structure not directly in the path of the main projectile?
I get what Doc is saying about barrier blind JSPs to the best for GP work because you don't know if the threat is going to be behind something but from all the gel shots Ive seen the fragmenting rounds do seem to have a larger wound channel than the bonded JSPs.
I think the big question everyone in this thread wants answered is whether or not we are giving up terminal performance when going from a fragmenting OTM to the bonded JSP in unobstructed shots. In my non-expert opinion Id rather have a fragmenting rounds for unobstructed shots and bonded JSPs for obstructed shots but seeing as how we dont have the luxury of knowing what shots we're going to have to take Id rather go with a barrier blind load.
The point I'm trying to make is the fragmenting is inconsistent and not solely dependent on velocity. Why would you think that a round that MIGHT fragment and then again might NOT would be superior to one that expands consistently.
The point I'm trying to make is the fragmenting is inconsistent and not solely dependent on velocity. Why would you think that a round that MIGHT fragment and then again might NOT would be superior to one that expands consistently.
Just a thought....
Big game hunters, consider a bullet that fragments a failure. Controlled expansion and maximium retained bullet weight are what big game hunters desire.
Varmint hunters like over expanding, fragmenting bullets because the animals they hunt are small and inadequate penetration is not a problem. The effect of those fragmenting bullets on a small animals are similar to the effect of a 20 MM HE projectile exploding within a human body.
The bottom line is, we settle for inconsistant fragmenting bullets because of the Hague Treaty restrictions on expanding bullets. What we would really like is an expanding bullet.
I will reconsider the above when big game hunters declare that fragmenting bullets are now their preferred bullet for taking big game.
Fragmentation is a very inconsistant wounding mechanism. The bullet must undergo a multi-step process which is spin destabilization, yaw, tumble, then fragmentation through lateral shearing force. More necessary steps means more things that can go wrong resulting in no fragmentation. If there isn't enough velocity to cause adequate lateral shearing force, if the bullet doesn't have enough rearward weight imbalance to cause rapid destabilization, if the bullet has too much sectional density it will not rapidly destabilize, if the bullet is too long it will have trouble tumbling, if the AOA isn't very good the bullet will not destabilize, if the there is a bullet construction error it will not frag, if there isn't enough water-lace issue in the path for the bullet to do the full multi-step process........etc, etc. The list goes on and on.
Expansion bullets on the other hand, will usually reach full terminal effects capability in only 2" of tissue, and their wounding mechanism only needs to have tissue in the path of the bullet. The water in the tissue causes rapid expansion with good reliability and at reduced velocities. It is simple, reliable, and effective. It makes for the ideal combat, hunting, and self defense round.
I reload Mk 318's alot and have got 2900fps out of a 14.5" barrel with 25.5grs. of W748. I would not feel undergunned with my load and would expect it to perform as it should. I have even shot at cinderblock at 100 yards and the bottom kept on truckin' after going through both sides.
I regularly shoot this load out to 300 yards and can hit an old acetylene tank 9/10 times when I do my part.
With a longer barrelled weapon it would be interesting to see the velocities and results.
Fragmentation is a very inconsistant wounding mechanism. The bullet must undergo a multi-step process which is spin destabilization, yaw, tumble, then fragmentation through lateral shearing force. More necessary steps means more things that can go wrong resulting in no fragmentation. If there isn't enough velocity to cause adequate lateral shearing force, if the bullet doesn't have enough rearward weight imbalance to cause rapid destabilization, if the bullet has too much sectional density it will not rapidly destabilize, if the bullet is too long it will have trouble tumbling, if the AOA isn't very good the bullet will not destabilize, if the there is a bullet construction error it will not frag, if there isn't enough water-lace issue in the path for the bullet to do the full multi-step process........etc, etc. The list goes on and on.
Expansion bullets on the other hand, will usually reach full terminal effects capability in only 2" of tissue, and their wounding mechanism only needs to have tissue in the path of the bullet. The water in the tissue causes rapid expansion with good reliability and at reduced velocities. It is simple, reliable, and effective. It makes for the ideal combat, hunting, and self defense round. Khan Rad, this is the most thorough and well stated description that I have personally seen on the effects of both types of bullets. If you have no objections I'd like to save and print and file this for future reference.
Just a thought....
Big game hunters, consider a bullet that fragments a failure. Controlled expansion and maximium retained bullet weight are what big game hunters desire.
Varmint hunters like over expanding, fragmenting bullets because the animals they hunt are small and inadequate penetration is not a problem. The effect of those fragmenting bullets on a small animals are similar to the effect of a 20 MM HE projectile exploding within a human body.
The bottom line is, we settle for inconsistant fragmenting bullets because of the Hague Treaty restrictions on expanding bullets. What we would really like is an expanding bullet.
I will reconsider the above when big game hunters declare that fragmenting bullets are now their preferred bullet for taking big game.
I'm not a hunter so I really would like this confirmed, but don't hunters dislike fragmenting bullets because they don't want to be chewing on lead after they prepare the meat?
If the data from Barnes is believed to be accurate, the Barnes 55 gr RRLP at 5.56 velocities would seem to be the ultimate HD round. It performs amazingly through all barriers-vehicle doors, wallboard, plywood- except for auto glass. The TC is one of the best I've seen for this caliber. Any thoughts?
http://ammo.ar15.com/project/Ballistic_Gel_Experiments/BARNES/Barnes_5.56_55gr_RRLP.pdf
I'm not a hunter so I really would like this confirmed, but don't hunters dislike fragmenting bullets because they don't want to be chewing on lead after they prepare the meat?
I am an avid hunter and have been so for at least 40 years. When hunting big game you definitely do not want a fragmenting bullet. I personally want a bullet that maintains as close to 100% of it's weight as possible, expands properly and preferably completely penetrates through the animal. When using a fragmenting bullet in big game the likelihood of wounding and not killing the animal a very good. Another problem with fragmenting bullets and large game is when they hit sold bone. They usually do not penetrate through the bone and only wound the animal. So, yes give me a stout, well expanding bullet that penetrates through hard bone and still leaves an exit wound every time.
75gr tap t2 on top
bottom 2 are 50gr BH tsx (8" and 20" bbl I believe), both pics are from online and mashed together. The dye in the bottom makes the tc look a little more impressive, but there is dye up top also. As you can see, you don't lose much going with a non frag round, but you greatly increase the chances of reaching vitals going through intermediate barriers.
intermediate barriers could include an arm raised with a gun pointed at you. That fragging round will not penetrate a sternum well after it has fragged through an arm. A bonded or other barrier blind round will. This is the problem I see with the rrlp (I am NOT an expert - so its just my $.02)... if you have to shoot through the arm, it may perform like bare gel and not penetrate where it needs to. When people are attacking, there arms are often in front of vitals. As you can see, though, the 75gr tap has a longer neck which may make it less of an issue. For HD, there is less worry about barriers, depending on your house, so everyone has a unique situation. That said, the RRLP does look promising. I'd love to hear an experts opinion on the round. I am finished rambling now.
http://i253.photobucket.com/albums/hh63/vinnyraf870/gel_zpsc7fefe0e.png (http://s253.photobucket.com/user/vinnyraf870/media/gel_zpsc7fefe0e.png.html)
Megade,
Please check the pdf I linked to. The RRLP round seems to provide explosive fragmentation even after passing through steel, plywood or wallboard.
B
I've seen military RRLP go through a car door as well as M193 at a VTAC course. RRLP is just a warm-fuzzy term, don't believe it unless you're just trying to shoot steel without too much splash!
Megade,
Please check the pdf I linked to. The RRLP round seems to provide explosive fragmentation even after passing through steel, plywood or wallboard.
B
I did. Looks great for certain situations, but I would rather have a bonded jsp or tsx for gp.
My post was mainly to show that the tc is comparable in frragging and non fragging rounds.
I'm not a hunter so I really would like this confirmed, but don't hunters dislike fragmenting bullets because they don't want to be chewing on lead after they prepare the meat?
no. penetration on animals is the significant factor. bullets disintegrate inconsistently so any bullet that strikes bone, ligaments, or other tissues not flesh will make for inconsistent results in the field.
hunters often talk about bullets that will "plow through" hide, bone, gristle, cartilage, etc. on raking or off-angle shots to reach the vitals. many prefer through and through shots. this is significantly deeper than vitals on a human...
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