During the run-up to World War 2 (1939-1945), the RGD-33 infantry hand grenade was selected to succeed an aging stock of Model 1914 grenades that held design origins in the First World War (1914-1918). The RGD-33 retained the "stick" design popular with the previous war but added a host of modern features - making the new weapons somewhat complicated to mass produce and use. Design work on the RGD-33 took place in 1933 but the series was abandoned in production as soon as 1942.
The basic design of this grenade incorporated a cylindrical head with a slimmer, cylindrical body. The head contained the main charge, primer-detonator, and TNT filling surrounding a central tube. The body served as a handle for one hand for when managing the safety pin slide and latch with the other. Overall weight reached 500 grams and overall length was 190mm. The TNT filling weighed 85 grams.
The grenade's action involved a time-fuse delay that, once activated, provided the operator with 4- to 5-seconds before detonation. Like the Model 1914 before it, a thin metal jacket could be applied to the grenade to make it an anti-infantry fragmentation-minded weapon, this increasing overall weight to 750 grams.
Serial production of the RGD-33 allowed for a widespread reach which, in turn, allowed the series to see considerable combat service in both Soviet war with neighboring Finland (the "Winter War" and the subsequent "Continuation War") during World War 2. It was also used by Communist forces in the Korean War (1950-1953) and the Vietnam War (1955-1975) that followed.
Despite its appeal, the grenade was simply too complicated and, therefore, too expensive to produce under wartime conditions - particularly after the German invasion of the Soviet Union through "Operation Barbarossa" in June 1941. As such, its successor was quickly found in the RG-42 "canister" grenade of 1942. Stocks of RGD-33 grenades were captured by the advancing Germans and redesignated as "HG 337(r).".