My department bought 10 Bushmaster SBR several years ago. Out the one's I checked, two bolt carriers(all were semi-auto) were properly staked and one was marginal. After a few hundred rounds the marginal one shot loose. None of the end plates were staked and several shot loose. They would feed lightly loaded ammo just fine that would barely cycle my personal AR's though. Last year they bought a bunch of Bushmaster ORC carbines. Same deal with the carriers and everything else that was supposed to be staked plus no backup sights and EoTech's.
