Premier Body Armor Multi-Hit Capable Level IV STRATIS Plates

@Kinetics In fairness, M855 is pretty darned good at armor penetration, especially for something so readily available to civilians. M855 can often punch through hard armor (most notably polyethylene) that can stop lead-core .308 and .30-06.

As for .30-06 M2 AP, it's an old design, but it's still a hell of a penetrator. I'd be very surprised if the 7.62x39 AP rounds you mentioned could penetrate better than M2AP.

All in all, IMO the claims made by this manufacturer describe some pretty respectable capabilities for the weight listed. Whether the claims are accurate is another question.

@50calHal Quick question, I'm pretty sure that even if M855 penetrates Lv3 armor, the veolcity should be sapped off enough that it basically pencil-holes through you like an overhyped 22LR, no?

Sure, that's still a hole, but that's a lot less deadly than fragmentation, yawing, and massive displaced and ripped tissue.

@Uncle Yar What you say makes sense, but it's hard to say for sure what the terminal effects would be. The bullet would lose energy for sure, but it might actually yaw and fragment earlier after going through a plate than it would have otherwise. So you might actually end up with a shallower but messier wound. Then again, it might just pencil through as you suggest. It's a good question, and I suspect the answer depends on a lot of variables (angle at which the bullet hits the armor, bullet velocity, exact armor materials, etc.).

@50calHal We need to gel test this.

@Uncle Yar The tests I've seen where M193 or M855 punch through a steel plate or Level IIIa soft armor, does a fair amount of damage to ballistic gel behind it. Absolutely less than unprotected, but pretty much going to get you out of the fight entirely and lethal if it ends up pencil holing through anything of importance. Often carries some of the steel from the plate with it in to the wound to a depth of a couple of inches on top of that.

At least for steel armor, M855 typically will not penetrate Level III armor. M193 will. Against hard steel armor, you want velocity. Against soft armors, something hard is more important. M855 will typically zip right through any kind of PE plate unless it is ridiculously thick without something to break it up first. Which is why any Level IV armor I've seen with PE incorporates You have to break the integrity of the penetrator and then the PE easily deforms and catches it. BTW, I mean relative hardness. An M855 uses a soft steel tip which is significantly softer than steel armor. Once you get in to true AP with hardened steel penetrators, tungsten carbide, etc. then hardness matters again vs a similar weight projectile of a similar diameter at a similar velocity.

Yes there would be some difference, but a mild steel bullet weighing 62gr traveling at 3000fps against hardened steel armor is going to have at most a nominal advantage in penetrating than a copper jacketed lead bullet weighing 62grs and traveling at 3000fps. However a 55gr FMJ at 3300fps has much better penetrating value against that hardened steel.

PE on the other hand will deform that copper jacketed lead bullet, spread the impact and stop it. The mild still tipped bullet won't significantly deform and tear a small hole right through.

An M2 AP .30-06 on the other hand is going to zip through PE armor even better than an M855.

7.62x39 light armor penetrating ammo is generally a mild steel core (still not hardened), but is a larger portion of the bullet compared to 5.56 M855 where its about 1/3 of the front of the bullet. IIRC the 7.62x39 LAP the entire core of the bullet is mild steel. Anyway, great against barriers. Not so great against armor. It'll penetrate Level IIIa soft armor for sure. I wouldn't want to bet Level III PE armor against it, but it just might stop it. Its a wider bullet moving significantly slower than M855. M855 vs 7.62x39 are pretty similar sectional densities, but the 7.62x39 is trucking along 600+fps slower. It certainly will not penetrate any hardened steel Level III armor (certainly not any of the III+ steel or ceramic armors or Level IV of course).