A few hundred weapons were made in November 1941. Another 155,000 were made over the next five months. By spring 1942, PPSh-41 factories were making around 3,000 weapons a day. The PPSh-41's design was good, as it allowed many weapons to be made in a short amount of time (mass production). Other examples of this kind of design were the M3 submachine gun, MP40 and the Sten. Its parts (except the barrel) could be made by unskilled workers. The PPSh-41 used 87 parts, and the PPD-40 used 95. The PPSh-41 could be made in 7.3 hours. However, the PPD-40 took 13.7 hours. The making of the barrel was often made simpler by using barrels made for the M1891 Mosin–Nagant rifle. The rifle barrel was cut in half. From this one rifle barrel, two PPSh-41 barrels were made. The barrel was then altered for the 7.62mm Soviet submachine gun cartridge.