The 8.8 cm KwK 43 (Kampfwagenkanone —"fighting vehicle cannon") was an 88 mm 71-calibre-length tank gun designed by Krupp and used by the German Wehrmacht during the Second World War.

The 8.8 cm Pak 43, an anti-tank gun, was very similar in design but mounted on tank destroyers or deployed stand-alone on the field.

This had minimal to no effect on the performance of the gun, but made replacing a worn-out barrel much faster and easier than before.

In addition, the massively increased operating pressures of the new gun also required a new armour-piercing shell to be designed.

Above that set amount, the expected barrel wear combined with the narrower driving bands of the PzGr.39-1 would lead to a loss of pressure and therefore muzzle velocity in the gun.