For compatible fixed-barrel host firearms only. Do not use on pistols with unlocking or moving barrels.

The SilencerCo AC633 Alpha Direct Thread Mount is a 1/2x28 direct thread suppressor adapter for compatible SilencerCo Alpha mounting systems. It allows a compatible suppressor to attach directly to a fixed threaded barrel without using a quick-detach muzzle device.

SilencerCo describes Alpha Direct Thread Mounts as a simple mounting solution that can shorten the overall suppressor setup compared to an ASR mount. This makes the AC633 useful for compatible fixed-barrel hosts where a compact direct-thread setup is preferred.

1/2x28 Direct Thread Mount: The AC633 model uses 1/2x28 barrel threads, a common thread pitch found on many 9mm, .22 caliber, and smaller-bore threaded host firearms. Always confirm your actual barrel thread pitch, caliber, and suppressor compatibility before ordering or installing.

Alpha Mount Compatibility: SilencerCo lists Alpha Direct Thread Mount compatibility with fixed rifle barrels on the Spectre 9, Omega K Series, and Alpha MAAD Brake. Some dealer references also associate AC633 with compatible Omega K, Octane, and Harvester 300 configurations; always confirm the exact suppressor model and mount interface before use.

Not for Unlocking or Moving-Barrel Pistols: SilencerCo warns this thread mount is not for use on pistols with unlocking or moving barrels. Tilting-barrel semi-automatic pistols generally require the correct piston and booster/Nielsen device setup instead of a direct thread mount.

Important Fitment Note: Always confirm suppressor model compatibility, Alpha mount interface, barrel thread pitch, caliber, bore clearance, host firearm action type, shoulder geometry, torque requirements, and alignment before installation or live fire.

Related Gear: Browse more SilencerCo products, shop additional silencer direct thread mounts, or view compatible silencer mounts and adapters.