Fire forming

The term fire forming in firearms refers to the process of thermomechanically reshaping a metallic cartridge case to optimally fit a new chamber by firing it within that chamber.

After fire forming, the spent case will take on the new dimensions of the firearm's chamber.

Fire forming is the final process in creating a wildcat or an improved cartridge.

This first method is the most common and will create a wildcat cartridge.

The factory cartridge is then fired in the chamber of the firearm.