Magazine - Pistol, Beretta, Model 1934 (M1934) Italian Serial number 591773. [With magazine and holster - 25 November 2009] The 9mm Corto (.380 ACP) round is less powerful than most other military service pistol cartridges, such as 9mm Parabellum or .45 ACP. The magazine capacity is only 7 rounds. When the empty magazine is removed it no longer holds the slide back. The slide will come forward and close the gun unless it is held open by application of the safety, a separate operation, and this slows down the reloading of the pistol.