Where by the barrel is coated via being placed in sacrificial jaws that are turned on it, as if held in a vice by them. The sacrificial jaws are the coating material and made of zinc, magnesium, copper, aluminum, brass, or perhaps more expensive metals.
May have unique military applications/ effects.
The jaws can be heated.
Also there can be a fixative agent or process to the coating.
Inexpensive way to achieve a different effect. That effect might be rustproofing or unique finish.
Copyright 2017 Thomas Murphy