From what I understand, only the loaded M855 cartridges are legal for sale to the general public, the projectiles themselves are not.
This brings up some interesting questions in my mind. I admit I am not well versed in the specific details of all the armor piercing ammo laws, and must ask others here to correct me if I am in error.
As I understand it, some time ago the govt. restricted AP rifle ammo. No more sale, although possession was still allowed. Loaded ammo. NOT the bullets. Those could still be bought and sold, as bullets, only.
I do know the AP ammo disappeared from the gun shows. Bags of AP bullets (and I'm talking .30 cal) appeared instead, and can still be found, here and there. Pulldowns from the banned ammo.
I don't recall exactly how they legally define rifle AP, but I think the M855 penetrator insert does not qualify.
A different law, with a different definition of what is AP, for handguns came later. m855 ammo, was not considered handgun ammo at the time. Handguns firing .223 Rem/5.56mm did exist at the time of the law, but there were no repeating handguns in that caliber on the market.
And the decision to classify M855 ammo as AP pistol ammo has not yet been finalized. IF it is designated handgun AP, it creates an interesting paradox.
Can reason upset the law? Or can only the law upset reason?
How can the same round, fired from a barrel over 16" and from a firearm possessing a buttstock not be armor piercing in law, if when fired from a barrel less than 16" and from a firearm without a buttstock it is armor piercing in law?