The two main anti-tank rifles used by the German Army were 7.92mm Panzerbüchse (PzB) model 38 by Rheinmetall-Borsig and model 39 by Gustloff Werke. Only 1600 PzB 38 were produced from 1939 to 1940, as the weapon was too complex and expensive.
Lighter PzB 39 was mass produced (some 39232) and was widely used on all fronts. PzB 38 weighted 16.2kg, while PzB 39 only 12.6kg. Both anti-tank rifles had similar characteristics - muzzle velocity of 1210mps (PzB 38) vs. 1265mps (PzB 39) and length of 1.615m (PzB 38) vs. 1.620m (PzB 39). Both rifles were single shot weapons and fired the same ammunition (steel core and from 1940, tungsten core).
The original bullets had hardened steel core and tiny capsule of tear gas. The idea behind the capsule was that once the bullet entered the armored vehicle it would disperse and force the crew to leave the vehicle. It didn't work as only the core penetrated and capsule was left outside.
PzB 38 and 39 were able to penetrate 25mm of armour at 60 degrees at 300m and 30mm at 100m. It was planned that each infantry division will have 81 rifles but it varied from unit to unit. PzB 38 remained in service in the early war years, while PzB 39 remained in limited use until 1943/44.
Majority of PzB 39 anti-tank rifles was converted to grenade launchers - Granatbüchse Model 39 (GrB 39). GrB 39 was a PzB 39 converted to take the standard rifle attachment grenade launcher (Schiessbecher) able to fire standard hollow-charge anti-tank or anti-personnel grenade.