Everybody? The market has indicated otherwise.
The ability to fire armor piercing ammo: the the 5.7's "claim to fame"..... rings quite hollow since such ammunition (AP) is also available for pistols in sufficient calibers where such ammo is legal to possess.
Everybody and anybody can own 5.7 armor piercing ammo that actually performs in soft tissue after it penetrates. There are no other calibers that offer such performance short of a prototye and/or extremely restricted production round making it practically inaccessible.
The SS190 is the standard factory armor piercing round which was found by NATO and many others to be the better choice against armored targets. I carry an aftermarket round that performs MUCH better than the SS190 shown in the following video. The round that I carry will actually leave a fist-sized cavity behind the IIIa armor and continue to penetrate 10 inches. Jealous yet?
Watch the magic!
http://www.youtube.com/watch?v=DtisZ9lT9Vs