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Posted On: 5/15/2023
By: Trevor
A: Great question Trevor! Very old military surplus cartridges can have what's known as "corrosive primers." It doesn't mean the ammo is questionable; it just means it will destroy your firearm with rust unless you take special steps while cleaning. When a corrosive primer ignites, it deposits hygroscopic residue inside the firearm's chamber and barrel. When a chemical is "hygroscopic," that means it attracts moisture from the air and retains it. If hygroscopic residue is allowed to remain inside a firearm, the water it attracts will cause rusting. That rust absolutely will destroy the firearm. Now here is the important thing: normal cleaning will not remove hygroscopic residue. You need to take additional steps while cleaning in order to save the firearm from certain destruction. Some people use hot soapy water. Some use boiling water. Some use Windex, or a 1:10 Ballistol/water solution. They are all effective!