The Griffin Plan A taper mount adapter in 1.125×28 is the low-profile interface that lets a pistol silencer with 1.125×28 internal threads accept Griffin Taper Mount muzzle devices (Griffin part no. TMA1125x28). Griffin Armament builds it from billet-machined 17-4 PH stainless steel in its Watertown, Wisconsin shop and finishes it black nitrided. It adds only 0.430 inch of length to the host silencer, so the setup stays compact on a pistol or carbine. Griffin lists it for SilencerCo Octane, Octane 9K and Octane 45K models, Rugged Obsidian silencers and Griffin pistol silencers. This is the 1.125×28 version of the Plan A family, so match the thread to your can before you order.

Key Specifications

• The silencer-side internal thread is 1.125×28, the pitch Griffin lists for SilencerCo Octane models, Rugged Obsidian silencers and its own pistol silencers.
• The adapter is billet-machined 17-4 PH stainless steel, a tough alloy that holds up to repeated mounting and heat.
• The finish is black nitrided, which resists wear and corrosion on a part that gets handled often.
• It adds 0.430 inch of length to the host silencer, keeping the overall package short.
• The mounting system is Griffin Taper Mount, and installation needs no proprietary tools.

Frequently Asked Questions

Which silencers does the 1.125×28 Plan A fit? Griffin lists it for pistol silencers with 1.125×28 internal threads, including SilencerCo Octane, Octane 9K and Octane 45K, Rugged Obsidian models and Griffin pistol silencers.

What does it let me mount? It gives the silencer a Griffin Taper Mount interface, which opens up Griffin Taper Mount muzzle devices and accessories.

Do I need special tools to install it? No. Griffin states it requires no proprietary tools.

Buy the Griffin Armament Plan A Taper Mount Adapter, 1.125×28

A mount adapter only does its job when the thread matches, and the 1.125×28 version is the one cut for pistol-pattern silencers. It keeps the added length to under half an inch and uses an American-made, billet stainless build. Order it with other suppressor parts and accessories from our Lubbock, Texas gun shop for fast direct shipping.