The Sturmgeschütz or in short StuG III started out as a self-propelled infantry support tank but became one of the most successful tank destroyers of World War Two. Its German designation was Sd.Kfz. 142/1.
The first versions of the Sturmgeschütz tanks had, like the early versions of the Panzerkampfwagen IV, the short 75 mm gun. These guns were underpowered in tank battles. In the early Western theatres of World War Two tank battles were not that common, but in the Soviet Union the Panzers encountered the T-34 and the KV-1 tanks, which had sloped armor. The Short barrel L/24 with a length of 176 cm had a penetrating capacity with the Panzergranate 39 at 500 meters of 39 mm. The later StuG versions with the 7,5 cm StuK 40 L/48 with a barrel length of 385,5 cm had at the same distance of 500 meters and the same Panzergranate 39 an amor penetrating capacity of 91 mm. The Panzergranate is a German armor piercing shell.
At 1000 meters the Panzergranate 39 did not exceed a height of 2,50 meters, so a T34 with a height of 2.76 meters within a range of 1000 meters could be fired upon with a flat trajectory shot and a hit was far more easy to accomplish. On the later G version side skirts were added as protections from anti-tank rifles and hollow charges.
