The "Karabin przeciwpancerny wz.35" was extensively used during the Invasion of Poland of 1939 by most Polish units. After Poland was overrun by Germany and the Soviet Union, large numbers of the weapon were captured. By 1940, Germany had pressed 800 into service as "Panzerbüchse 35 (polnisch)" (PzB 35(p)) and later PzB 770(p), and sped up work on their own simplified, one-shot anti-tank rifle "Panzerbüchse 39" (PzB 39). Germany replaced some of the captured Polish DS ammunition with their own 7.92 mm hardened-steel-core bullets.