US Patent 11402173 Retention system

A handguard assembly includes a handguard and a key. The handguard includes a receiver surface that faces toward a receiver of an associated firearm and a muzzle surface that faces toward a muzzle of an associated barrel of the associated firearm and in an opposite direction as the receiver surface. The handguard extends between the receiver surface and the muzzle surface so as to define a longitudinal direction. The handguard defines a key bore extending in the longitudinal direction from the receiver surface toward the muzzle surface. The key is received in the key bore of the handguard so as to be surrounded by the handguard such that the key is concealed from view when the handguard is installed on the associated firearm.