In contrast, the .38 Long Colt uses a bullet, the bearing surface and lubricant of which are entirely contained within the cartridge 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.