For sale - WWI&II German 9mm ammo

[Johnny Peppers]

The actual term "corrosive primer" is a bit misleading. The primer in of itself is not corrosive, but upon firing the primer combustion produced potassium chloride, which like sodium chloride is very hygroscopic. The inside of a gun barrel, especially a cut rifled gun barrel, has many nooks and crannies for these particles to hide out in. As these particles attracted moisture, a brine solution was left in the bore. Just a wipe with an oily rag did not remove all the potassium chloride, and it started doing it's damage. The old timers used water first to flush out the particles of potassium chloride before resorting to their normal bore cleaning procedure.

Black powder is much the same in that it is not actually corrosive, but the combustion of the mixture left a hygroscopic compound in the weapons barrel and the moisture did the damage.