Questions about performance of SS109 in an AR pistol

[CrazyFingers]

The purported reasons for the M855 ban proposal were “armor piercing pistol rounds that are a danger to law enforcement.”
In order to avoid this thread being deleted/locked as a repeat of other M855 discussions, my specific questions for those more knowledgeable are:

1. Is there a minimum muzzle velocity for an SS109 projectile to reliably penetrate soft body armor?
2. Is the barrel length of an AR pistol capable of generating this muzzle velocity?

I realize the specific wording of FOPA uses physical projectile characteristics to define “armor piercing ammunition” and does not discuss whether a given round is actually capable of doing so.
In short, I’m curious to know whether it is even possible for an average AR pistol (arguably the least concealable “handgun” ever made) to fire an “armor piercing round” that can actually penetrate armor.

[MegademiC]

I’m pretty sure nearly all, if not all 223 ammo Will penetrate soft armor, even out of a pistol.

5.7 penetrates with the “special” ammo and it’s anemic compared to 223.

357 mag will penetrate a lot of soft armor. I think level 3 is where it starts to offer protection. I’m sure someone more knowledgeable will chime in.

[Onyx_Z]

I’m pretty sure any rifle ammo (at rifle velocities) will penetrate soft body armor…

[CrazyFingers]

@Onyx_Z

I’m pretty sure any rifle ammo (at rifle velocities) will penetrate soft body armor…

Thanks Onyx Z, this is the basis for my questions: Can an AR pistol generate these velocities?

[markm]

Agreed. Short of downloading a round to a silly low velocity, it’s going through soft body armor.

[militarymoron]

@CrazyFingers

Thanks Onyx Z, this is the basis for my questions: Can an AR pistol generate these velocities?

Here’s an article on barrel length effect on muzzle velocity for M855: http://www.sadefensejournal.com/wp/?p=1093

it’s still going at 2200 fps out of a 7" barrel, so i’m pretty sure it’ll still go through a level IIIA panel.

[Kain]

@militarymoron

Here’s an article on barrel length effect on muzzle velocity for M855: http://www.sadefensejournal.com/wp/?p=1093

it’s still going at 2200 fps out of a 7" barrel, so i’m pretty sure it’ll still go through a level IIIA panel.

Didn’t the MAC do a test against level IIIa hard armor with liberty defense what 50gr 9mm that defeated the armor going about 2000fps? I wpuld say the smaller projectile going faster would have nary an issue with level lla soft armor in this case.

[CrazyFingers]

Thanks for your replies.
That’s the information I was curious about, whether the ostensible rationale for the ATF’s proposal was even physically possible. Since it is, I suppose that removes one (of many) reasons why it was an absurd idea.

[MegademiC]

@CrazyFingers

Thanks for your replies.
That’s the information I was curious about, whether the ostensible rationale for the ATF’s proposal was even physically possible. Since it is, I suppose that removes one (of many) reasons why it was an absurd idea.

It’s absurd because 855 does nothing any 223 won’t do. I can imagine where this might go, but I’m not stating it on a public forum and giving stupid people stupid ideas.

[markm]

An article was posted in the Green tip ban thread that shows where the top thug at ATF says ALL .223 ammo poses a thread to LE due to pistol ARs. This is where this ban was intended to go in the long run.