The Panzerbüchse 39 (pronounced pan-zer-beuk-se), or PzB 39, is a German anti-tank rifle.
The PzB 39 was an improvement over the Panzerbüchse 38. It featured only the PzB 38's barrel, while the other parts were different. The PzB 38 was used until 1944, where they were hopeless against all but the lightest vehicles.
Some of the rifles were converted to Granatbüchse 39s (GrB 39) starting from 1942, where they had a shorter barrel measuring only 590mm and an affixed "Schiessbecher" (firing cup) so that it could fit a rifle grenade. The Schiessbecher was the one used on the ubiquitous K98K, and was interchangeable.
The PzB 39 was an improvement over the PzB 38's design. The PzB had a slightly shorter barrel and decreased weight, as well as a new mechanism. The PzB was fitted with a falling block mechanism, where the breech block falls down in order to load a round. Rocking the pistol grip backwards makes the breech block fall. This also ejects the spent cartridge. To combat the decreased rate of fire of the PzB 39, two ammunition cans, each containing ten rounds of 7.92x94mm ammunition were affixed to the side of the rifle to increase its practical rate of fire.