Guntec Ar15 Muzzle Device Shim - 4pc Kit 1/2x28

The Guntec AR15 Muzzle Device Shim - 4pc Kit 1/2x28 is a precision alignment solution designed for shooters who demand repeatable, zero-shift performance from their AR-platform rifles. Muzzle device shims address a critical issue in modern tactical and competition shooting: tolerance stack-up between the barrel threads and the muzzle brake, compensator, or suppressor mounting surface.

This four-piece shim kit contains precision-engineered shims that mate with standard 1/2x28 threaded barrels—the most common pitch found on mid-length and carbine-length AR15 uppers in 5.56 NATO and .223 Remington. By stacking shims selectively between the barrel shoulder and your muzzle device, you achieve true concentricity, ensuring the device's bore axis aligns perfectly with your barrel bore. This eliminates runout, reduces baffle strike risk on suppressed systems, and maintains consistent point-of-aim across barrel changes or device swaps.

Law enforcement armory personnel, military gunsmiths, and serious competitive shooters benefit most from this kit, particularly when standardizing multiple rifle builds or troubleshooting chronic accuracy issues. Installation is straightforward, making it accessible for both experienced and novice users.