How soon to clean after shooting corrosive ammo?

[GXW]

Humidity is the main factor.

Corrosive primers use potassium chlorate which converts to potassium chloride after firing. This is a salt essentially equivalent in rusting properties to sodium chloride = common table salt.

In addition, some of the by-products of combustion are hygroscopic (water absorbing), so when the air is humid they actively absorb moisture from the air. Once you have moisture plus salt plus iron, its just a matter of time before you have rust.

Hey MauserMike, The hygroscopic effect makes so much sense. I couldn't figure out why the rust started so fast but that explains it.

Thanks.

 

[GXW]

Also, a guy at the range on Friday told me tht he stores his SKS in a hard case with a couple of packs of desicant to absorb moisture. Seems like a good idea.

 

[MauserMike]

From experience in the lab, potassium chloride is not so hygroscopic. But many other potassium salts are, e.g. there is potassium nitrate, which is in the bore for sure after firing for sure.

Hey MauserMike, The hygroscopic effect makes so much sense. I couldn't figure out why the rust started so fast but that explains it.

Thanks.

 

[animalamidon]

after firing 250 rounds through my sks and letting it sit for 2 DAYS there was enough rust on the piston that it was pitted after it was cleaned. clean ASAP!