This 223 ammo is weird. Not all will cycle in an ar. It appears underpowered. It may work with a pistol gas system or with a suppressor. It'd be great for plinking or bolt action, but I bought it to test fire builds and inconsistent ammo is no good for me. You could maybe break it down and reload it if desired too. Bought from an online reloader. Mixed head stamps. Comes in bags of approximately 250 rds for $50/bag (20 cents per round). about 4k rounds available. Located in Clinton.