A rail cover for use on a handcover having a rail. The rail cover includes a body having opposing side edges, a top surface and a bottom surface. Parallel sidewalls depend from the bottom surface to define a socket therebetween for slidably engaging the rail of the handguard. A snap clip is carried by the body and is movable between a raised position for allowing sliding engagement with a rail of a handguard and a lowered position wherein a portion thereof is received within a slot of the handguard and prevents sliding engagement thereof.