The Norwegians came to the same conclusion as most European Nations during the years post WW1 and that was that their 6.5x55SE was not powerful enough for machine gun use. The 7.92×57 M.98 was in use in Norway, but they introduced a new caliber with the case extended to 61mm and a 14.2 gram (219gr) bullet. The 7,92×61 was adopted in 1937 and manufactured by Raufoss until 1944, but was still used up to the 1960’s. To distinguish the new 7,92 Norwegian from the standard 7,92×57 M.98 it was called TUNG, which means heavy, as opposed to the 7,92×57 M.98 being called LETT, or light. The Colt M.29 machine gun in use in Norway was adapted to the new round, with the idea to convert all existing M.29’s in service at that time but the German invasion put that on hold. Consequently, there were M.29’s chambered for both during the conflict causing confusion everywhere.

Tracers of the 7.92×61 [Tung (heavy)] round had the same steel-plated 11 gram (170gr.) projectile used in the Norwegian 7.92×57 [Lett (light)] rounds. It gave a greenish colored trace out to 1,000-1,200m. During 1943 a new 12 gram (185gr.) projectile was introduced with a different tracer compound that had better ignition and burned with a yellowish color.