For serious shooters, USA Ammunition is the ideal choice for training, competition or a long session at the range. The easily identifiable white box means high quality and reliability at a low price. This ammunition is new production, non-corrosive, in boxer primed, reloadable brass cases.Specifications:Brand Winchester AmmoCategory Centerfire Rifle RoundsCaliber 5.56 NATOModel USABullet Weight 55 grRounds Per Box 20Casing Material BrassApplication Recreational ShootingBoxes Per Case 50Bullet Type Full Metal Jacket (FMJ)Muzzle Energy 1306 ft lbsMuzzle Velocity 3270 fps