The 51T S.T.A.M.P Mount from AAC is an accessory fast-attach mounting system compatible with both legacy and current production 51 Tooth muzzle devices manufactured to AAC specifications. The S.T.A.M.P Mount enables users to quickly and easily install or remove a silencer to or from a 51T muzzle-device-equipped host firearm with one hand, using an intuitive motion and gross motor skills. The S.T.A.M.P Mount (Spring Tensioned Accessory Mounting Platform) features an internal ACME thread and a spring tensioned internal feature that provides solid, wiggle-free engagement with 51T muzzle devices. Secondary retention is provided by a coil-spring tensioned, toothed pawl with a textured thumb pad. The pawl axis pin is easily removable in the teeth on the pawl wear and pawl replacement becomes necessary. The S.T.A.M.P Mount features industry-standard 1.375-24 threads for compatibility with most current production silencers. Note, will not work with MITER style 51T mounting system.