Premium, American-Made 300 Blackout Ammunition Loaded with a 147 grain full metal jacket (FMJ) projectile, this factory new 300 AAC Blackout ammo delivers reliable performance at 1,800 feet per second. Each box contains 100 rounds of clean, consistent, boxer-primed brass. The 300 Blackout cartridge—also known as 300 AAC, 300 BLK, or simply Blackout—has earned its reputation over the past decade as an effective short-range option for thin-skinned game, especially within 100 yards.