CMMG 55DA38D Low-Profile Gas Block .750" Black Chrome Moly Steel

The CMMG 55DA38D is a low-profile gas block built for AR-15 platforms using barrels with a .750" gas journal diameter. Machined from durable Chrome Moly steel and finished in a non-reflective black coating, this non-adjustable gas block delivers the slim profile and heat-resistant strength needed for reliable cycling with modern free-float handguards.

The low-profile design sits close to the barrel so it tucks inside slim free-float handguard systems, giving the user more clearance for accessories along the full length of the rail. The block is secured to the barrel via set screw mounting and ships complete with the required installation screws and a gas tube roll pin, making installation straightforward for anyone assembling a custom upper or upgrading an existing build.

The 55DA38D is a solid choice for builders piecing together a free-float upper from scratch, replacing a worn or loose factory gas block, or reconfiguring a rifle around a different handguard profile. Sized for standard .750" gas journals and built by CMMG, it pairs naturally with most mil-spec gas tubes and barrel nut setups on the AR-15 platform.