A discussion of rifle ammunition bans and .223/M855 murders, by the numbers.

[benEzra]

107. "Unlikely but possible"

I pretty much believe everything you wrote. But you say 'particularly unlikely' a handgun could do it, ergo unlikely but possible.

It is "unlikely but possible" that someone will drop a lottery ticket on my front lawn that wins me millions, too.

It is exceedingly unlikely that someone could retrieve an AR "pistol" from any sort of concealment and shoot several rounds into a dime sized target or smaller in a second even under no-stress conditions, never mind under stress. It is several orders of magnitude more likely that one could retrieve a pistol from concealment and put one round through a football-sized target in a couple of seconds.

As far as I am aware, there are no cases whatsoever of .223 penetrating Level III armor on the street since NIJ ratings were invented, whether from rifles or "pistols".

As to the feasibility of shooting through Level III armor with an AR "pistol" by shooting multiple rounds through the same hole, it turns out that modern Level III plate is apparently even tougher than I previously thought, based on the videos below. Here is an amateur video of a guy (who thought M855 is AP, FWIW) being surprised that a basic plate of Level III armor stands up to more than 60 rounds of M855 out of a rifle (looks like an 18" to me):

At 2:36, after 30 hits with M855, he shows where four M855's have hit a spot roughly the size of a dime, without penetrating.
At 4:08, ~50 hits on the same plate with M855 from a rifle, still no penetration.
At 5:43, after 90 hits on the same plate with M855, the plate has become deformed and weakened to the point that 2 rounds have finally slipped through.

Keep in mind that this is from a rifle, with considerably more energy at 35 yards than an AR "pistol" would have with the muzzle pressed directly against the armor.

Now, check out one round of regular lead-core 55-grain FMJ out of a 22" barrel at close range, against the same brand and rating of armor that stopped 60+ rounds of M855 above:

2:31, the very first hit from 55-grain lead-core FMJ penetrates right through the armor.
4:14, a round of green-tip M855 does not penetrate, but harmlessly disintegrates.

Advocates of a ban on M855 want to ban the second bullet above (the one that didn't penetrate). Does that really make sense?

FWIW, a round of actual 5.56mm AP (M995 tungsten core) would penetrate that plate at a few hundred yards; M855 is most assuredly not AP.

What is, or what would you gauge, a 'handgun'/.223 recoil rating as? whatever scale they use.

Recoil can be expressed in terms of free recoil energy (which takes into account linear recoil only, but is a nice, neat measure of recoil magnitude); shot to shot splits will also be affected by muzzle jump or wobble from shot to shot. In terms of free recoil energy, a typical AR pistol should between 1.5 and 2 times the recoil of a typical AR-15, depending on weight and configuration, or roughly comparable to a 7.62x39mm or .243 Winchester rifle.