From: http://world.guns.ru/smg/smg33-e.htm German MP-40 Sub Machine Gun MP-40 submachine gun, with shoulder stock opened View attachment 594 MP-40-II submachine gun, with sliding dual magazine housing (see insert) View attachment 595 Caliber: 9x19mm Luger/Para Weight: 4,7 kg loaded, 4,03 kg empty Length (stock closed/open): 630/833 mm Barrel length: mm Rate of fire: 500 rounds per minute Magazine capacity: 32 rounds Effective range: ca. 100 meters MP-40 was also produced in a number of variations, which differed in shape of certain parts; also, toward the end of the war, several production shortcuts were introduced to save the costs of manufacturing. probably the most interesting variation of the MP-40 were the MP-40-II and MP-40-II. These guns featured dual magazine housings which hold two magazines in a laterally sliding bracket. This increase the total ammunition capacity "in the gun" to 64 rounds, in a desperate attempt to catch up with 71-round magazine capacity of Soviet PPSh-41. The later variant, MP-40-II, was made in limited numbers, but turned out to be a failure - sliding dual-magazine housing was a constant source of jams and failures, and was very sensitive to dirt and fouling. Nevertheless, MP-38 and especially MP-40 submachine guns were of good design, and set the pattern for so called "second generation" of submachine guns ("first generation" being represented by the wood-stocked and carefully machined MP-18, MP-28 and the like). The second generation weapons usually were of compact design, and made using mostly steel stampings and pressings, or castings. It also must be noted that many MP-40 that survived the WW2, continued to serve up until late 1970s or early 1980s, in few European armies such as Austrian or Norwegian.