SilencerCo AC1278 ASR Flash Hider 9/16x24 LH 30 Cal Black Nitride

The SilencerCo AC1278 is an ASR Flash Hider built for .30 caliber rifle barrels that use the less-common 9/16"x24 left-hand thread pattern. It belongs to SilencerCo's Active Spring Retention (ASR) family of muzzle devices, giving the shooter a single point of attachment that works as a stand-alone flash suppressor and also serves as a quick-detach mount for any ASR-compatible SilencerCo suppressor.

At the muzzle, the AC1278 dramatically reduces visible flash to help preserve the shooter's night vision and keep their position obscured in low-light conditions. The Black Nitride finish hardens the surface and provides strong corrosion resistance for hard field use, while the self-centering ASR interface locks a compatible suppressor up tight with no play and breaks away cleanly when it is time to go unsuppressed.

Because the AC1278 uses 9/16"x24 LH threads, it is intended for specific .30 caliber host platforms that call for that non-standard pitch and left-hand orientation - it is not a drop-in for the typical 5/8x24 RH AR-10-style barrel. Always confirm your barrel's thread pattern and hand before installing.