I dunno. You have a .223 bullet with a speed of 2300fps and energy of 395 ft lbs, about three times the speed to inflict a fatal wound. Very low, almost unnoticeable recoil on an AR platform. 50 rounds to solve your "problem". Any more than that usually requires air support. You can get ammo from frangible to armor vest piercing.
Obviously I have one. ;-) And I like it. Very accurate, fun to shoot, ammos costs not too bad, and my personal favorite defense piece. Also matches with my choice of pistol, the FN Herstal 5.7. To add, both my pistol and carbine have worked flawlessly over hundreds of rounds.
