Back in the wild, wild west there was a saying, “Don’t let the sun set on a gun that you shot today.” Ammunition primers were so corrosive that they would almost immediately start to rust and corrode the firearm. Most of the commercially available ammunition that you buy today is non-corrosive. There is still some surplus military ammunition that has corrosive primers that will leave behind corrosive gunshot residue. Your chamber and bore will corrode if you do not clean them after shooting. If you shoot any ammunition that isn’t listed as being non-corrosive (or doesn’t say), make sure that you properly clean your firearms as soon as possible after shooting.
There are many methods, but they all involve this:
- Rinse salts out with water.
- Dry.
- Clean/lubricate as normal.
- Inspect the rifle 2-5 days after to ensure there is no rust.
The Savannah Arsenal Project 