So I recently shot some supposedly corrosive ammo in my pistols and did not clean them.  So far they show no signs of rust, corrosion, basically just dirty like always.  So how and when can you tell if ammo is truly corrosive?  It does help that it is currently Winter and there is low humidity in the air.

Don't clean it and leave it in the closet for 5 years.  


I helped a friend clean a nice older relic.  He had done exactly this.  Along with substantial corrosion, a pinhole or two had completely penetrated the chamber.  


Why even worry about it?  Change your cleaning solvent to MPRO-7 and you won't have to worry about it at all.

c'mon, friend! clean them pistols!

if you know you shot ammo with a corrosive primer, this is a NO BRAINER.

Example: I just put sugar and sand in your vehicle's gas tank––you can't see it...BUT

The only thing that's "corrosive" is the primer, and all it does is deposit salts in the gun.  It's the environment and those salts that cause corrosion.  Here's how you find out whether or not a batch of ammunition is corrosive:

1) pull a bullet from the suspect ammo and dump the powder.

2) obtain a piece of mild steel sheet, and thoroughly clean and degrease it

3) "pop that cap" about 12" from the steel-just a primer here, nothing more

4) clean the BEE JEZUS out of the gun.  Do it twice.

5) Leave the steel out in the air for 48 hours.  Check it at 12 hour intervals.  If you see a rusty "bloom" after about 12-24 hours at the place where you pointed the muzzle, it's corrosive.  If you see no FOCUSED, WELL DEFINED change where you pointed the muzzle after over 48 hours, it's not.

Primers CAN be "mildly corrosive" or "OH MY GOD corrosive."  It it's at all corrosive, clean the gun thoroughly after each use.

Most of you are missing the point of this post.  I am not chomping at the bit that I will have a rust mess of once beloved guns due to corrosive ammo.  I am looking for *scientific* means to test if ammo is corrosive or not.  I bought ammo and was told that it was non-corrosive and shot some of it.  Now I am told that it is corrosive, yet I don't necessarily want to return the ammo.  My only basis to test if it was truly corrosive or not  at the time was an unclean gun.  Thanks to GHPorter for the response I was looking for, as I will try it this weekend.  

BTW The ammo that I bought is differs by a decade of years compared to what is sold most recently.  This is why I believe mine to be non-corrosive.  The manufacturer could have switched primers in those 10+ years.

Most of the corrosive surplus ammo is from the former Soviet Union/Eastern Bloc.  Russia didn't switch to non-corrosive primers until ~1994, so all Eastern Bloc surplus should be treated as corrosive.

Some unscrupulous dealers like Southern Ohio Gun and Cheaper Than Dirt put "non-corrosive" in the ammo description, even if it is obviously highly corrosive (50's Soviet, Yugoslavian, etc)

What about Russian Brown Bear ammo. it says non corrosive but it is soviet?

The soviet union fell in 1991. Welcome to ARFCOM


Brown bear, silver bear, wolf, and every other ammo manufacturer in the world these days are safe. I don't know of any that are still using corrosive primers.