Carl Gustav M / 45 Kulsprutepistol m / 45 ( Kpist m / 45 ) , also known as the Carl Gustav M / 45 and the Swedish K SMG , is a nine mm Swedish submachine gun designed by Gunnar Johnsson , adopted in 1945 ( hence the m / 45 designation ) , and manufactured at the Carl Gustafs Stads Gevärsfaktori in Eskilstuna , Sweden . The m / 45 was the standard submachine gun of the Swedish Army from 1945 to the late 1990s . It was gradually replaced in Swedish service by updated Ak 4 and Ak 5 assault rifles . The last official user of the m / 45 , the Swedish Home Guard ( Hemvärnet ) , retired it from service in 2003 . 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 . The first production version was adopted in 1945 as the Kpist m / 45 . The Danish Hovea M / 49 SMG , although similar in appearance , is not a version derived from the m / 45 . The Hovea was a development of the failed test contender ( fm44 ) from Husqvarna Vapenfabrik AB . Features . 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 . Accessories include a special sub - caliber barrel ( painted silver ) for firing blanks and low - powered gallery ammunition . When firing blanks , a cone shaped blank firing adapter must be attached to the threaded muzzle of the sub - caliber barrel ( and secured by a clip ) to ensure the mechanism has adequate pressure for its blowback operation . Other accessories include night sights ( war - time use only ) that attach to the fixed day sights ( f : protected post , r : L - type ) , a brass catcher for collecting spent cartridges ( peace - time use only , for reloading and recycling ) , a quick - detachable ( by attached cord ) ejection port cover ( painted bright red ) for guard duty which secures the bolt from accidental firing and a speedloader ( rarely issued due to limited availability ) that loads the 36 - round magazine in seconds . The m / 45 was also issued with a standard cleaning kit containing a threaded cleaning rod , threaded jag and a container for the jag , lubricant and cleaning patches . The standard sling issued was made of leather , attached to the rear left receiver and left barrel - sleeve sling bars . The 36 - round straight detachable staggered row box magazine is wider at the rear than at the front , the extra space allows the 9 mm Parabellum cartridges to feed more efficiently in dusty environments and sub - zero temperatures . The trapezium design makes the magazine very reliable , because magazines of parallel - side design are more likely to jam under adverse conditions . The magazine was used post - war by Finland in the M / 31 Suomi under the designation m / 54 , a distinguishing feature of the variation m / 55 ( made by Lapua ) is a steel wire carrying loop mounted at the bottom front edge . The basic design idea of the m / 45 magazine was also used for the magazines of the Czech model 23 and model 25 and the French MAS submachine guns . The m / 45 has no safety switch . Instead the m / 45 is put in " safe " by sliding the cocking handle into a short side - slot above the main ( lock ) slot . In the example US Army photograph , this short safety side - slot is visible behind the rear L - sight . This design feature results in a somewhat longer time to ready the weapon for firing , because the soldier must " remove " his right hand from the pistol grip and trigger , as if operating a bolt - action rifle . When the m / 45 is unloaded the bolt is locked in place in the bolt - forward position by pushing the cocking handle downwards , engaging a hole in the lower left receiver wall . Manufacture and use . The Carl Gustav M / 45 was replaced in the Swedish armed forces during the mid - 1990s with the AK 4 and AK 5 . 2 April 2007 kpist m / 45 was officially declared obsolete when it was retired from Hemvärnet who were the last users in the Swedish military . In addition to Sweden , several other countries have used and the weapon , with versions of the weapon being produced in Egypt and the U . S : Licensed production in Egypt . The m / 45 has been manufactured under license in Egypt as the " Port Said " and the " Akaba " . The tooling needed for production , as well as technical assistance , was sold by Sweden to Egypt during the 1950s . The Port Said looks and functions exactly as the M / 45 while the Akaba is a modified and simplified version . The Akaba has no barrel jacket and a slightly shorter barrel and the folding butt stock has been replaced by a telescoping wire butt stock similar to the one used on the US M3A1 and the French MAT - 49 sub machine guns . The simplified sights of the Akaba were moved to the front ( unprotected post ) and back ( protected peep ) of the receiver . Usage by the United States in southeast Asia . During the Vietnam War , the US Navy SEALs used the Carl Gustav m / 45 SMG extensively . One of the gun ' s qualities which appealed to the Navy was that the M / 45 can fire almost immediately out of the water ( over the beach ) . It also saw use by CIA operatives and advisers . In US service it was largely known as the " Swedish - K " or " K - Rifle " . The US Navy was so impressed by the m / 45 that when Sweden embargoed the export of weapons to the USA in 1966 , Smith & Wesson was given the task of producing a copy . This was designated the Smith & Wesson M76 . However , by the time when the M76 was ready for combat deployment , the US Navy had ended most SEAL missions in Asia . Many of the m / 45s used by US forces and agencies were " sanitized " , which means that they were devoid of any markings , implying clandestine use . During the 1980s , MK Arms manufactured the MK - 760 ; it is a copy of the Smith & Wesson M76 . One variant used by the Navy SEALs used a modified M3 suppressor . Heavy , cumbersome and lacking in service life , it was soon replaced by a Swedish made suppressor .