The .41 Rimfire Cartridge was first introduced by the National Arms Company in 1863 and was also known as the .41 Short and the .41-100. In most designations like this, the second number refers to the black powder load, though in this case it means "41 hundredths of an inch". According to "Cartridges of the World," the .41 Rimfire consisted of a 130 grain (8.4 g) lead bullet propelled by 13 grains (0.8 g) of black powder in its original load. The round produced a muzzle velocity of feet per second ( m/s) and a muzzle energy of foot-pounds force ( J). In contrast, modern low-powered smokeless cartridges produce considerably more energy: .380 ACP (200 ft·lbf), .22 LR (100 ft·lbf).