FYI. A dude is selling black tip SS190 AP 5.7x28 ammo on Arfcom EE for 10$ a round. Might be worth buying a few since they are next to impossible to find for civy purchase
http://www.ar15.com/forums/topic.html?b=7&f=133&t=655624
http://www.ar15.com/forums/topic.html?b=7&f=133&t=655624