Ar-15/M16 Adjustable Gas Blocks - A2-Style Gas Block .750 Bore, Black, Stainless Steel

Replaces the factory front sight/gas block and allows you to tune the gas system for smoother cycling and operation. Especially critical on match and varmint rifles when shooting both factory and custom-loaded ammunition. Simple setscrew lets you control the gas flow, so you can customize the setting for each load. Hex head setscrews clamp the block securely to the barrel. Installation instructions included. This is a standard-height A2 front sight gas block, not the taller "F-marked" height.