.45 ACP - Cartridge Dimensions

Cartridge Dimensions

(Diagram not to scale)

The .45 ACP has 1.62 ml (25 grains H₂O) cartridge case capacity.

.45 ACP maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).

The common rifling twist rate for this cartridge is 406mm (1 in 16 in), 6 grooves, Ø lands = 11.23mm, Ø grooves = 11.43mm, land width = 3.73mm and the primer type is large pistol. The cartridge headspaces on the mouth of the case at the L3 datum reference.

According to the official Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives guidelines the .45 ACP case can handle up to 130 MPa (19,000 psi) piezo pressure. In C.I.P. regulated countries every pistol cartridge combo has to be proofed at 130% of this maximum C.I.P. pressure to certify for sale to consumers. The SAAMI pressure limit for the .45 ACP is set at 21,000 psi (140 MPa), piezo pressure, while the SAAMI pressure limit for the .45 ACP +P is set at 23,000 psi (160 MPa), piezo pressure.