The sub-machine gun, Carl Gustav M45, also known as the Swedish K, is a small compact 9mm weapon of light weight and sound construction. It is magazine fed and operated on the blow back – heavy bolt system. It can be fired in any position.
The M45 was the standard sub-machine gun of the Swedish Army from 1945 to 1965. It was gradually replaced in Swedish service by updated Ak 4 battle rifles and Ak 5 assault rifles. The last official user of the m/45, the Swedish Home Guard (Hemvärnet), retired it from service in 2007.
The standard m/45 is a fully automatic only weapon without any option for semi-automatic fire. It weighs 3.3 kg (7.3 lbs.) unloaded, and 4.2 kg (9.25 lbs.) loaded with a 36-round box magazine. It is 808 mm (31.8 in.) long with the stock extended, and 550 mm (21.7 in.) long with the stock folded. The m/45 is an open bolt design with a fixed firing pin. The relatively slow cyclic rate of fire (550–600 rds/min.) and low recoil of the bolt-mechanism actuation (straight blowback) makes it easy to control during full automatic fire. Single shots are also easy to achieve (with very little training) by letting go of the trigger before another round is cycled. The m/45 is fairly accurate up to 200 meters.
The m/45 SMG was developed in 1944–45, with a design borrowing from and also improving on many design elements of earlier submachine guns. The sheet metal stamping techniques used in making the German MP 40, the British Sten, and the Soviet PPSh-41 and PPS-43 were studied in detail. Two designs were tested in 1944, one from Carl Gustafs Stads Gevärsfaktori and one from Husqvarna Vapenfabrik AB and the prototype from Carl Gustafs Stads Gevärsfaktori was chosen for further development.Carl Gustav M45