Boy is this getting old.  No matter what you shoot or what you are shooting things like this are going to happen.  I shot a coyote at 150 yards with a .280 remington, 145 gr. boat tail bullet at about 3000fps. Rolled the dog, it got up and ran.  Walked out to where it had been hit.  A double handful of lungs were on the ground and a large blood trail.  Walked the trail and 150 yards up the wash the the coyote was dead.  I have shot a bunch of coyotes with a .223 and most have dropped in their tracks, one I shot with a 64 gr. winchester power point got up and ran off.  We have killed two deer with the 64 gr. bullet (it is legal here in Nevada) and they went down within 50 yds.  Most deer hit with the .280 drop where hit, however I had one that I shot at about 225 yds that ran up hill about 75 yds then turned down hill and piled up.  When I cleaned it the heart was cut in half, one leg was shot in two and it had a hole in the off side.  Placement, penitration and expansion were all perfect, the deer and the coyote just did not know that they were done.  If you want 100% stops use something with wheels.  Rant over.  Bb      

5.56mm does the job just fine.  There are always statistical outliers with any round -- read Bing West's No True Glory about Fallujah -- he mentions an insurgent that took a head shot from a Marine sniper's 7.62mm bolt gun and not only did not die, he didn't even stop running with most of his jaw flopping. 

 

   Apparently the 5.56 is so ineffective, that insurgents are having to hide roadside bombs at night.

I don't believe this. How many times must it be said that in order to immediately kill, small arms must generally hit a vital organ. Short of that, weapons effects are wildly variable. No new round will make a difference at all so long as it relies on conventional KE principles and is limited by treaty obligations. Wanna increase effectiveness? More training and not new weapons. Gotta put those rounds here...

<img src="http://upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Heart-and-lungs.jpg/230px-Heart-and-lungs.jpg">

...Short of that, good luck because thats just what it will be.


DA

Physics, physics, physics. Unless that round can put a lot of concentrated work into the animal like tearing out whole soccerball size chunks of flesh upon impact, the 50-100 kg mass of protoplasm is just going to act like a giant hydraulic shock absorber lump of jello held together by what acts like rubberbands, string, encased in a thick rubber balloon overlaying a mild steel lattice frame.

People have no idea how tough it is, to stop something like that with a 4 gram moving mass.

Herald

OK guys I admit I am sticking my nose into something about which I am not an expert, but the type of round does make some difference right?    Assuming all other things are equal Darth, would you rather be hit by a .223 or .308 (or a .50)?       I don’t think anyone makes the argument (and I could be wrong) that switching to a larger round would suddenly insure that every bad guy grazed in the arm would suddenly drop dead.   It is a matter of odds.    If you are increasing the chance of debilitation with a single torso hit by 15% then isn’t that significant and worth discussing?   I’ll admit there are other considerations to weigh (amount of ammo that can be carried, ability to deal with bigger recoil, etc.), but a bigger more powerful round will increase the odds in the shooter's favor.  

 

I seem to remember a nationwide FBI study on “one shot stops” by police.   As you went up the scale of commonly used rounds you jumped between 5 and 10% per increase (9mm on the bottom, then 10mm, .40, .45 .357 on the top if I recall correctly). 

Let's say the 15% improved chance of stopping a target is a valid number (as good as any other number, as I don't think there's any accepted number for how much harder 7.62x51 thumps than 5.56x45).

 

In exchange for your 15% improved kill/incapacitation rate, you give up 50% of your basic load of ammunition.  With most any weapons system, you give up 1/3 of your magazine capacity, so you have fewer rounds in the gun and more frequent reloads. 

 

Harder to quantify, but you also give up engagement speed.  Guns chambered for full-power rounds are heavier, making them slower handling (we'll ignore full length barrels, since they can be 16" or shorter barreled weapons, same as 5.56mm).  Recoil is notably heavier and while a lot of knee-jerk macho types think any consideration of recoil is just girly, the truth is you have to overcome that recoil to drive the gun back onto target or two drive it onto the next target.  There are some potential fixes to this (lighter bullets like the Hornady 110 grain TAP), but AKs and 6.8mm Rem SPC, 6.5mm Grendel, etc., all sling 110-130 grain bullets at combat ranges in much more compact and lighter formats.

 

The long and the short of it being that there is no free lunch with small arms ammunition, and no perfect solution.  The problem replacements for 5.56mm run into repeatedly is that it is as good or better as any of the other compromises out there.  Lethality complaints exist on the internet from vague sources, but no one I know who's put M855 into bad guys has had any problem with them not being killed or incapacitated rapidly.  There are documented cases where the round did not drop folks, but there are also documented cases where 7.62x51 did not get the job done.  If we started using 350 grain .50 Beowulf rounds tomorrow, there'd be stories of failure to stop by the day after tomorrow.  People can be hard to kill.

 

Americans are gadgety folks by nature and we tend to always thing technology is the fix, but this is a case where technology doesn't offer "better" just a shuffling of trade offs.  The answer is training, not gadgets.  Teach troops to employ controlled pairs at CQC ranges, teach them how to at least hit targets at longer ranges, and teach them realistic (non-Hollywood inspired) understanding of wound ballistics.  The kit we have works, though not all users know how to make it work. 

 

Here is the big problem. We do have a scientific model for Probability of Incapacitation. However it is first of all a simplification, and secondly even it only predicts the probability of a bullet incapacitating a target within 30 seconds of the target being hit, which is about as fast as physiological processes can incapacitate a target. Unfortunately 30 seconds is an eternity in combat.  Any incapacitation more quickly than that is caused by either a hit to the brain or spinal cord, by psychological factors acting on the target (sometimes referred to as the "I've been hit!" phenomen), or perhaps by some other factor or group of factors that we don't understand.

 

A larger bullet might be more effective at stimulating the "I've been hit!" response. It might generate more shock that might create incapacitating effects on the spine even without directly hitting it. It might effect some other elusive set of factors that might otherwise incapacitate a target more often.

 

The question is, how much of an increase in stopping power is needed to counterbalance the increased weight of weapon and ammunition, and the lower quantity of ammunition that can be carried? If there is an increase in immediate stopping power of larger caliber ammunition, can this be convincingly and objectively demonstrated? Even more importantly, can it be quantified with sufficient clarity that we can make an educated cost-benefit analysis between more round and better rounds. Until such objective data can be produced there is no basis on which to make a choice of another round over the 5.56mm.

 

Unfortunately the only way I can see to get this kind of data is go issue weapons chambered with each of several rounds to be tested (5.56x45, 7.62x39, 6.8mm, 7.62x51 etc) but otherwise as similar as possible to troops. Then get detailed after action reviews of their performance, recovering bodies when possible to confirm where the targets were hit and such. After each round has been used on 100 or so targets, then put it all together to get a comprehensive model of what happens when a particular kind of round hits a target. Then we'd have good data to make a cost benefit analysis about what works best. Is this going to happen? Probably not.