Originally designed for use with blackpowder, the .45 Colt is one of the most powerful, commonly available handgun cartridges when loaded with smokeless powder. Starline's .45 Colt brass has been tested to .44 Magnum pressures in gun systems suitable for such loads. *New brass may require neck sizing for use with .452" and smaller bullets.Specifications and Features: Caliber 45 Long Colt Unprimed Brass Made in the U.S.A.