First Breach .223 REM 55 Grain Full Metal Jacket Boattail New C220 Brass Cased Rifle Ammo 20 Rounds 223 55 loaded. 223 REM FMJ 55 grain match-grade ammunition. FB USA .223REM Headstamp. Specifications for First Breach .223 REM 55 Grain Full Metal Jacket Boattail New C220 Brass Cased Rifle Ammunition: Manufacturer: First Breach Caliber: .223 Remington Number of Rounds: 20 Bullet Type: Full Metal Jacket (FMJ) Bullet Weight: 55 grain Cartridge Case Material: Brass Package Contents: First Breach .223 REM 55 Grain Full Metal Jacket Boattail New C220 Brass Cased Rifle Ammunition Ammunition Tray First Breach 223 55 loaded: .223 REM 55 Grain Full Metal Jacket Boattail New C220 Brass Cased Rifle Ammo 20 Rounds