Dual-magazine MP40 variant allowing a second magazine to be slid into position when the first was empty without a reload — effectively doubling the ammunition without reloading. Rare variant, issued primarily to vehicle crews. Type: Submachine Gun Action: Blowback Caliber: 9mm Luger Capacity: 64 Year introduced: 1941, Germany Weight: 112 oz Overall length: 24" Status: Discontinued Military use: Yes Intended use: military