The A.R.M.S. #41-B Silhouette folding front sight gas block — a low-profile, spring-loaded front sight designed for 0.750" barrels on AR-15, M4, and M16 platforms.
The A.R.M.S. #41-B is one of the few folding front sight gas blocks that functions as both a reliable gas port and a repeatable-zero iron sight. Manufactured by Atlantic Research Marketing Systems (A.R.M.S. Inc.), the Silhouette line has been a staple on precision and recce-style AR builds since the early 2000s. The folding mechanism uses a spring-loaded detent system that snaps the sight post into the upright position with enough force to hold zero under recoil, yet folds flat enough to clear magnified optics mounted on a full-length rail.
The "-B" variant omits the bayonet lug found on the standard #41, producing a narrower profile that clears most free-float handguards and satisfies state-level restrictions where bayonet lugs are prohibited. The sight post itself is a standard AR-15/M16 front sight post, adjustable for elevation with a standard sight tool. The clamp-on design fits barrels with a 0.750" gas block journal — the standard diameter for M4-profile and government-profile barrels.
We keep A.R.M.S. sights in stock when we can — they move fast with the recce crowd. Order yours today and we'll get it out the door.
