Looking at our go to Ammo Website, i.e. SGAMMO I see where the AR 5.56 platform beats out the AK47/74 is in ammo selection, the variety is almost endless. I see both Federal and Speer offer Law Enforcement Ammo to the public. Speer advertises expansion out to 200 yds in a 10" barrel, pretty good bragging rights for the 5.56. Two hundred yds in my opinon would be good enough for a SHTF, Apocalyptic, End of Times Zombie Killer, right?