Originally Posted by Night Driver
The best way to break down corrosive mercury primer salts is to use boiling water. Failing that the hotter you can get the water the better. G.I. bore cleaner specifically for cleaning corrosive primed ammunition used to be available in surplus stores but its been so long since the US made corrosive primed ammunition I doubt you will find any.
Don't be fooled by adds or notices that say; "Slightly Corrosive". Slightly corrosive is the same as being slightly pregnant. Get it?
Mercury fulminate is not used in any military small arms ammunition. Corrosive ammunition residue contains potassium chloride and related compounds that will quickly rust bare steel. They are highly soluble in water.
If mercury was present there would also be significant health problems. Mercury fulminate was commonly used with blackpowder loads, but when smokless powder came in the military switched to potassium chlorate mixtures for their small arms primers. The chance of finding mercuric salts is not even one in million after firing 7.62x39 ammo.