The National WWII Museum, Education Collection
When developing the assault rifle concept German designers need a round that was smaller than regular rifle ammunition but that had better range than standard pistol ammunition. A compromise was made; the Mauser rifle cartridge was simply shortened, producing the 7.92x33mm Kurz ammunition type. When stacked in groups of 25 or 30, this ammunition formed a curve, requiring a new type of curved magazine, which remains a common configuration on modern weapons.