Barnes .300 Blackout Ammo Features For those seeking ammunition that performs consistently Barnes Ammunition delivers higher velocity flatter trajectory and ultimate accuracy at an affordable price. Barnes the leader in bullet innovation offers shooters the ultimate in accuracy terminal performance and handloaded precision in a factory loaded round. Barnes .300 Blackout Ammo Specifications Ammo Type: Centerfire Caliber/Gauge: 300 AAC Blackout Caliber Description: 300 Blk Rounds Per Box: 20 Box Weight: 0.90 (lbs) Bullet Type: Jacket Hollow Point FB Bullet Weight: 120 Case Material: Brass