BCM LGB750 Low-Profile .750" Black Phosphate Gas Block

The BCM LGB750 Low-Profile Gas Block is a mil-spec replacement gas block designed for the AR-15 / M16 / M4 / M4A1 platform. Machined from steel and finished in black phosphate, this low-profile block clamps onto .750" diameter barrel journals and secures with set screws for a reliable, no-shift installation.

Built to USGI tolerances on all internal dimensions, the bore is honed after finishing to meet the original Technical Data Package (TDP) spec, ensuring consistent gas flow and reliable cycling. The low-profile design keeps the block tucked close to the barrel, making it a clean fit under modern handguards and rail systems, and an ideal drop-in for custom builds or replacement of worn or out-of-spec factory gas blocks.