The Automatgevär m/42, commonly known as the AG-42 or Ljungman (pronounced as Young-muhn), is a Swedish semi-automatic rifle which saw limited use by the Swedish Army from 1942 until the 1960s.
The Ag m/42 was designed by Erik Eklund of the AB C.J. Ljungmans Verkstäder company of Malmö around 1941, and entered production at the Carl Gustafs Stads Gevärsfaktori in Eskilstuna in 1942. Some 30,000 rifles were manufactured in all for the Swedish Army. This was a relatively small number of weapons and the standard infantry rifle remained the 6.5 mm bolt action m/96 Mauser.
Norwegian "police troops" trained in Sweden during World War II were issued a number of Ag m/42s and brought these rifles to Norway when the Germans surrendered in 1945. These rifles were never modified to the later Ag m/42B version.
After a number of issues had been discovered, including a serious problem with rusting gas tubes, the existing stocks of the rifle were modified between 1953 and 1956, and the reworked rifles were designated Ag m/42B. Modifications included a stainless steel gas tube, two knobs on the breech cover, a new elevation knob for the rear sight, a rubber case-deflector, new magazines and new cleaning rod. The Ag m/42B was replaced in Swedish service in the mid 1960s by the Ak 4 (derived from the Heckler & Koch G3).
In the early 1950's the Ag m/42B manufacture license was sold to Egypt resulting in the Hakim rifle, which uses the 7.92x57mm Mauser cartridge. Sweden sold the machinery to Egypt and the Hakim was therefore built with the same machine tools used for the Ag m/42B. Eventually, the Hakim was modified into a carbine using the intermediate-power 7.62x39mm Russian cartridge, called the Rasheed Carbine.
The Ag m/42 is operated by means of a direct impingement gas system, similar to that of the French MAS-49 rifle. The Ag m/42 also uses a tilting breech block like the Tokarev SVT-38/SVT-40, the MAS-49 and FN FAL rifles.
The Ag m/42 uses the 6.5x55mm cartridge loaded into a removable 10-round box magazine. In practice, however, the magazine usually remained attached to the rifle while it was loaded from the top with five-round stripper clips. Like the British Lee-Enfield and Soviet SVT-40, the Ag m/42's magazine was intended to be removed only for cleaning.