Nickled luger?

[Johnny Peppers]

Bill,

Colt's process of oven blueing did not draw carbon from the metal, but rather the animal bone and pure petroleum oil produced the carbon that colored the metal in the heat of the oven. When Colt went to the gas fired ovens, the pistol parts were on revolving racks which turned one direction for half the process time, and then reversed for the same amount of time in order that the pistol parts would blue evenly in the vapor.