AK - 4 Ak4 ( Automatkarbin 4 ) is the Swedish licensed copy of the G3 . It has since been replaced by the Ak5 in the regular army , but it is still in use in Hemvärnet ( Engl : Swedish national guard . ) Description . In the early sixties the Swedish soldiers personal armament consisted of submachinegun m / 45 , Autoloading rifle m / 42 or the m / 96 Mauser . Most of the rest of the western world had already mostly replaced SMG : s and autoloaders with a new concept - the assault rifle , a weapon with the SMG : s rate of fire and the rifles range and precision . The first assault rifle , Sturmgewehr 44 , was developed and manufactured in Germany during world war 2 . It was from that weapon that the young engineer Michael Kalashnikov developed his famous assault rifle , the Kalashnikov model 47 ( Ak 47 ) . The Germans had during the last months of the war designed an improved version of the StG 44 called StG 45M but when the war ended the plant was destroyed and the engineers fled abroad . Some engineers under the supervision of Vorgrimmer ended up in Spain where they continued their work . The result was a new weapon with technology from the StG 45M - Cetme . When the situation stabilized in Germany three of them returned to their country : Heckler , Koch and Seidel . In Oberdorf they founded the factory Heckler & Koch that in the beginning manufactured sewing machines until they could purchase the license rights for the Cetme rifle . After modifications the weapon was adopted by the west German army with the designation Gewehr 3 ( G3 ) . In Sweden attempts to replace the Ag m / 42 and SMG m / 45 were made . Trials with assault rifles were in progress since the fifties . The weapons tested were : The Gram was a Swedish manufactured assault rifle that was a development of the Ag m / 42 Ljungman . After the initial trials it was revealed that only the G3 och FN - FAL could face up to the specifications . After the final trials in the early sixties the G3 was modified in 40 places and was accepted as the Automatkarbin 4 . The G3 was superior to the FN - FAL because of its higher resistance to wear and lower price . The Ak 4 was manufactured between 1965 - 70 at the Carl - Gustaf Rifle factory and at Husqvarna weapons factory and after that until the end in 1980 only at the Rifle factory in Eskilstuna . The principal of operations on the Ak4 is a roller - delayed blowback breech system . The basic principle is rollers against tilted surfaces . The mechanism works as mechanical gears that makes the bolt to initiallymove four times longer than the bolt face . The purpose is to lessen the rate of fire without needing a heavy bolt to slow it down . The gas piston moves backwards through the gas pressure that is directed towards it through a hole from the barrel and affects the bolt to make it move backwards . The Ak4 is used today in units with fixed assignment where the weight of weapon and ammunition is less important . The Ak 4 is still a very good weapon that will remain in the inventory for a very long time . With a new Swedish developed armor piercing ammunition the weapon will be a very good and powerfulsystem well into the twentyfirst century .