Wax bullets are exactly what they sound like - a bullet made of a wax compound.
They may be used for Fast Draw competition, or simply as a cheap and easy way to practice with your single or double action revolver. In Fast Draw, wax bullets are often loaded into the shell just prior to going onto the shooting line. The bullet is simply pressed into place with your fingers, then a shotshell primer or .22 blank is placed into the specially counter-sunk hole at the base of the shell. Because of the ease of loading the wax bullet as compared to the process involved with creating a blank, many Fast Draw shooters practice with nothing but wax bullets. This also increases the skill of the shooter because of the increased accuracy required when shooting wax.