The .38 Long Colt, also known as .38 LC, is a black powder cartridge introduced by Colt's Manufacturing Company in 1875. In 1892, it was adopted as a standard military pistol cartridge by the United States Army for the Colt M1892 revolver. The metric designation for the .38 Long Colt is 9.1×26mm. It is slightly more powerful than the .38 Short Colt, also known as .38 SC. The original .38 SC and .38 LC differ in case length, bullet diameter, weight, and design and are not interchangeable; however, modern production .38 SC ammunition is now loaded with a smaller, internally-lubricated bullet which can be fired from firearms chambered in .38 LC or .38 Special. The modern .38 LC can be fired from .38 Special firearm, but not from a firearm designed for the .38 SC, since the case length is too long. Design and ballistics The .38 Long Colt's predecessor, the .38 Short Colt, used a heeled bullet of at a nominal , producing muzzle energy. The cylindrical "shank" or "bearing surface" of the bullet, just in front of the cartridge case mouth, was in diameter, the same as the outside diameter of the cartridge case (as in .22 rimfire cartridges). A smaller-diameter portion of the bullet, the "heel", was crimped inside the case mouth, and the lubricant was outside the case, and exposed. In contrast, the .38 Long Colt uses a bullet which on the outside of the cartridge case is only , the bearing surface and lubricant being entirely contained within the case. This kept the waxy lubricant from collecting grit which can damage the revolver's barrel. Colt, however, retained the single-diameter charge hole, resulting in the bullet failing to form a seal as it traveled through the chamber throat. This seal was expected to cause the bullet to expand in the throat and be "swaged down", or reduced again in diameter, as it entered the barrel, but uneven expansion produced poor accuracy. In the United States Army's original black-powder cartridge used by the Colt M1892 revolver, muzzle velocity from the revolver's barrel with bore diameter ( groove diameter) was with a bullet weighing , resulting in a muzzle energy of . In 1903, the Army changed its cartridge to smokeless powder and slightly tightened the revolver's bore to ( groove diameter); the new muzzle velocity was with a bullet of , giving a muzzle energy of .