The AG-42 (Halvautomatiskt Gevaer 42) Ljungman was Sweden’s first standard issue selfloading rifle. It was put into production in 1942, with only a one-year development period. It is a direct gas impingement design, with a gas tube feeds pressurized gas directly against the bolt carrier. Locking is done with a tiling bolt similar to a FAL or Tokarev design.
The Ljungman is a relatively heavy rifle (over 10 pounds unloaded), and combined with its standard muzzle brake and relatively light 6.5×55 cartridge it has little felt recoil. However, operating the AG42 is significantly different from almost any other autoloading rifle. The rifle has a bolt carrier and receiver cover that operate together. To manually retract the bolt, one pushes the receiver cover all the way forward which locks it onto the bolt, and then pulls it back along with the bolt. Subsequently pushing the receiver cover forward a fraction of an inch will release the bolt to slam forward, either chambering a cartridge or crushing your poorly-placed thumb (anyone who complains about M1-thumb has definitely never had a digit caught in an AG42 action).
The Ljungman was the standard Swedish infantry rifle into the 1960s, when it was replaced with a licensed H&K design. In 1953 the AG42 was upgraded to the AG42B model, which involved a number of small changes. The most distinctive one is the change from serrated patches on the receiver cover to round protrusions, to allow shooters a better grip. In addition, a rubber ejection buffer was added to prevent brass damage, the gas tube was strengthened, the magazine was give a more secure front hook, and a few other minor internal improvements were made.
In the early 1950s, Sweden licensed production of a Ljungman variant in Egypt, where it was known as the Hakim. These rifles have a few differences form the Swedish guns, including use of an adjustable gas port and being chambered in 8mm Mauser. Egypt also produced a Ljungman-based carbine in 7.62x39mm, called the Rasheed (or Rashid).
Madsen company catalog, including their licensed version of the AG-42B:
English (click to download in PDF format):