The companies of Krupp and Rheinmetall-Borsig received a contract to develop a replacement for the 50mm PaK 38 and the totally obsolescent 37mm PaK 35/36. They chose to base the weapon on a 75mm long-barreled gun, and the new weapon – the 75mm Panzerabwehrkanone (PaK) 40 – entered service at the end of 1941.

Like it’s earlier cousin, the PaK 38, it had a muzzle brake, sported a flat armor shield, and was mounted on two wheels with a split trail. However, because of the new weapon’s size and weight, the carriage was made of steel, and the design dispensed with the castor wheel on the trails used by the PaK 38.

The anti-tank round fired by the PaK 40 achieved a muzzle velocity of 930 m/s, and could penetrate 80mm of armor at a range of 1,000m: it was one of the most formidable anti-tank weapons that Allied crews had to face.

Its main prime movers were the Ost caterpillar and the 3-ton half-track. However, it was also mounted on a variety of vehicles and even was used by aircraft under the designation BK 7.5.