I like this one just as much as i like my bear creek side charge - CBC Industries AR-15 16in 7.62x39mm Complete Upper Receiver Rifle Kit

Pulled it out of the box threw in a enhanced pin and added a 100% mill spec lower with extended power hammer spring so that i can shoot cheep steel case ammo then i went up with 200 rounds loaded in mags. I threw all 200 rounds threw as fast as i was capable the hole front of this thing was smoking like it was about to catch on fire but it fed all 200 flawlessly and that is hart to find in 7.62x39 in a ar pre built upper so i bough another straight from the manufacturer