Bought this from ar15depot.com, installed and it ended up being too short for the rail I wanted to use. Never fired, only installed and taken right back off. Specs from site: PISTOL BARREL 7.5" 5.56 These barrels are chambered in 5.56 and have 1 in 9 twist, made from 4140 chromoly steel. SOLID BLACK FINISH COMES WITH M4 RAMP FEED Retail is $125 with free shipping. I'll sell for $100 FTF in the Gateway/Parkrose area.