AAC Blackout 51T Muzzle Brake Overview The AAC Blackout 51T Muzzle Brake delivers highly efficient recoil reduction while providing compatibility with AAC sound suppressors. Precision manufactured from aerospace-grade, heat-treated 17-4 stainless steel and finished with a durable SCARmor/nitride coating, it offers exceptional strength, corrosion resistance, and long-term durability. Designed for 7.62mm/.30 caliber rifles with 5/8x24 threads, the Blackout 51T features AAC's 51-tooth mounting system for secure suppressor attachment, making it a rugged and reliable upgrade for hard-use rifle platforms.