Guntec USA AR-15 Muzzle Device Shim Kit 1/2x28 4-Piece

The Guntec USA AR-15 Muzzle Device Shim Kit is a 4-piece indexing solution designed to properly time and align threaded muzzle devices on 1/2x28 barrel threads. Muzzle brakes, flash hiders, and compensators install against fixed barrel shoulders, and shimming lets the builder orient ports, top openings, or blast direction exactly where they want them and lock the device down tight without binding on the shoulder.

Built around the standard 5.56 NATO / .223 Remington thread pattern, this kit gives AR-15 builders a clean, clocked fit on common muzzle devices. The set includes one 1.5mm (.06") shim and three .15mm (.0055") shims, giving you multiple thickness options to stack behind the muzzle device shoulder so you can dial in the exact timing before final torque.

Made from hardened steel, these shims hold up to repeated installation and removal without deforming or losing their thickness. Whether you are installing a new compensator, clocking a blast can, or aligning a birdcage flash hider, the Guntec shim kit is the inexpensive, no-guesswork tool that gets the job right the first time.