If you are a high volume shooter, this is the ammo for you. Tulammo makes these smooth-cycling rounds in the popular military calibers 223 Rem, and 308 Win and 7.62X39. These cartridges use non-corrosive Berdan primer and bullets with a lead core and full bimetal jacket. The steel case has is bottled-shaped with non-projecting flange and a phosphate polymer coating.