The Noveske 300 AAC BLACKOUT is designed to run optimally firing both subsonic suppressed and supersonic unsuppressed. This barrel is tuned to lock back on the last round using subsonic 220 and 208 grain ammunition with a sound suppressor. The firearm may not lock back with subsonic 220 and 208 grain ammunition without a sound suppressor. Also, the subsonic 300 BLK ammunition is more susceptible to a malfunction due to carbon fouling and adverse conditions than supersonic ammunition. The barrel is tuned to operate correctly with the back pressure provided by the AAC 762-SDN-6 using an H2 buffer, or a Surefire 762K suppressor and an H buffer. In the development of this barrel, Noveske found evidence that the suppressor may require a symmetrical baffle stack as found in the AAC Cyclone K, 762-SDN6, and Surefire 762K suppressor. Suppressors which cause off axis turbulence, such as those with K type baffles, may cause baffle strikes and/or point of impact shift, and may damage your suppressor.
An "AR-15 Pistol" barrel is less than 16" in length. Pistol barrels are only for use on AR-15 pistol lowers and legal Short-Barreled Rifles. Other configurations may violate Federal law.