Federal Fusion 300 AAC Blackout 150 Grain MSR Centerfire Rifle Ammo is optimized for use in self-loading rifles such as the AR-15 and similar platforms. Gain peak ballistic performance with this Fusion round out of your short-barreled MSR. Fusion utilizes fast-burning, clean propellants that produce a low flash, and boost velocity in SBRs. The primer is optimized for use with free-floating firing pin designs. A molecularly-fused jacket over a pressure-formed core delivers exceptional accuracy. 300 AAC Blackout 150 grain Designed for use in short barrels Increased velocity