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Posted: 6/19/2007 11:04:10 AM EDT
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www.youtube.com/watch?v=dKhMOfaYwvE Interesting declassified comparo between a variety of MOUT weapon systems. Even with a long 20" barrel, the M16 had penetration difficulty. This is a real concern in Iraq, where insurgents use concrete structure for cover, firing their 7.62x39 with impunity through intermediate barriers. It's unfortunate that we are not fielding a better intermediate cartridge along the lines of the 6.8SPC, 6.5 Grendel, or 7.62x39. Some, in the civilian and LE sector may view the 5.56mm penetration difficulty as an asset. Many of us own who our rifles for potential SHTF scenarios, which may occur in urban settings like New Orleans, view that "asset" as a limitation when confronted by rounds with capability more suited for turning cover into concealment. Anyway, interesting video if you haven't seen it. Part two is also worth watching. |
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1. That was a 20"barrel with M855. 2. A shorter barreled M4 would have better penetration in those tests, an SBR even better. 3. If you are concerned about penetration use barrier ammo and you will pass the brick 45 degree and cinder block tests. Nothing wrong with 5.56 if you use the appropriate ammo and understand its capabilities. |
That's interesting. I'm aware that we would expect greater penetration through steel with a longer barrel, and less penetration in ballistic gelatin. However, you state that the shorter the barrel, and therefore decreased velocity, translates into better concrete penetration? It would be interesting to see some data to back that up. One would think the concrete is more similar to steel than ballistic gelatin. |
Military testing has already shown 5.56 M855 has decreased penetration in wood and other hard barriers inside 200m because it breaks up from too much velocity. M855 is a poor barrier round as it tends to come apart when passing through hard barriers. This leads to smaller weight pieces that do not have the capability to penetrate tissue very deeply or they tend to not penetrate seondary barriers beyond the first. If you want your 5.56 rifle to penetrate invest in some trophy bonded bear claw ammo. I have a little Federal Tacitcal 62 grain for that situation. It reamins in one soldid piece traveling in a nose forward orientation because it mushrooms up front and ends up nose heavy and it does not shed its jacket. It can penetrate laminated auto glass at a 45 degree angle and still penetrate 12" of ballistics gelatin. It also does not veer off course like many 5.56 rounds do when encountering hard barriers. |
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Well wasn't the requirement for ss109/M855 that it be able to penetrate a NATO helmet at 600M or something silly? Then it would hold that the secondary, close range fragmentation is just a happy accident of the velocity required to make that 600m shot with enough "oomph." The video is loading still, I am a little surprised/curious to hear that m855 (out of a 20" no less  ) doesn't do well.
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www.dtic.mil/ndia/2006smallarms/gandy.pdf Check out the 200M penetration data from the M16 with 4 different loadings (slide 22/24). Mk262 had issues penetrating VEHICLE DOORS and concrete. The only good concrete penetrator was M995. "If you can't penetrate the barrier then the target can't be reached". |
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Saiga any many Bulgarian AKs can achieve 1-2MOA. Seeing that the average engagement distance in Faluja was what--15 feet-- should be accurate enough. Then again, at the distances that 5.56 supposedly can use its accuracy advantage, the round is a non-fragmenting .22 that can't penetrate barriers. Fragmentation range on M4s with M855 is about 65 yards. How many rounds of M855 does it take to drop someone? Good thing we have 3 round burst. |
Funny how the Soviets gave it up in favor of the 5.45. |
Against Kalashnikov's wishes and even today no one bought into the concept. The 7.62x39 round generates about 30% greater energy transfer in a round that weighs twice as much and is made of mild steel. The .223 is great against open targets but not so great when targets are behind light cover then after a hundred meters it simply becomes a .22 once it loses it's fragmentation ability. Overall the 7.62x39 is a much better round for Urban Combat but the platform isn't as ergonomic. C77 |
It's the universal problem. No round is good for all applications. However, the 5.56 is better for more applications than 7.62 x 39. Given the lukewarm response to the 6.8, I don't see anything changing anytine soon. |
I'm a huge fan of AK's and have twice as many AK's as AR's. I love the 7.62x39 and 5.45x39 cartridges and I'm quite impressed with their perfomance. However, I agree 100% with the quote above. From 55gr M193 to 77gr Mk262, 5.56x45 will get the job done in more places with greater accuracy than than the Soviet/Russian/Warsaw Pact calibers. I know there are limited instances in which the x39 rounds may exhibit better performance than 5.56, but there are many more instances in which the opposite is true. |
| Years ago, we conducted an informal test. My friend got a 3/8" piece of steel and put it out at 25 yards. We shot at it with a 44mag(dimpled the surface), 9mmPara(dimpled the surface), 223Rem/5.56NATO-55g(cratered a bit, but did not penetrate), 7.62X39-steel cored(penetrated), 30-06(penetrated). |
Me and a buddy shot up an old Caprice at his farm like 5mos ago....(at 40yds).... M193 out of meh 16" S&W went through one door and barely dimpled the opposite M855 went in and out both icepick holes 75grn BHBB tactical went in and out both doors but it mushroomed and the opposite door had a twice as big hole We also shot the steel wheel of the car.... M193 barely chipped paint M855 dug about halfway through 75grn BHBB tore completely through it like it was paper Very informal but you get an idea of the different types of bullets |
I did not know that having a shorter barrel would increase the ammo's penetration through barriers. Does this only apply to the M855 ammo? Or is this across the board for other ammo like: 55 gr M193, 68-69-75-77 gr Matc-type ammo. As for your other comment that there is "nothing wrong with 5.56 if you use the appropriate ammo," I agree, but it's unfortunate that in order to penetrate intermediate barriers you trade off terminal ballistic performance as the bullet will probably not fragment (but I guess the more important thing is actually hitting the target!) And that's where the case for 6.8 SPC becomes stronger, because, it seems to me, that with the 6.8 SPC round you have a round that can penetrate intermediate and still have good terminal ballistics, right? Please correct me if I'm wrong. |
No kiddin its steel cored  Make it even try SS109 in .223(5.56) next time |
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