How to tell if ammo is corrosive?


December 28, 2006, 12:34 PM
Surplus newbie here, how can I tell if ammo is corrosive? This stuff ( is listed as "super clean", but does that just refer to the exterior of the shells? Powder fouling? Non-corrosive primers? Can I infer from the fact that they don't specifically say "Non-corrosive" that it isn't? Does the date or locale of manufacture give it away as corrosive? What about new manufacture ( Is there any way to tell by looking if I come across some rounds without knowing their history?

I know that's a lot of questions, but you all have a lot of answers. :D


(I just re-checked the Aim Surplus link and they've pulled the product. It was Bulgarian 7.62x54R, 1950s manufacture)

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December 28, 2006, 12:41 PM
From my limited experience, "super clean" and "corrosive" mean 2 different things.

"Super Clean" = clean burning powder w/ little residue/fouling

"Corrosive" = leaves behind deposits which accelerate/aide in causing rust which leads to pitting

Pretty much, any mil-surplus 7.62x54R ammo you get, will be corrosive...

I am sure more knowledgeable responses will follow.

December 28, 2006, 12:56 PM
IIRC, corrosive ammo uses potassium chlorate as the compound in the primers, among other things. This leaves a corrosive salt residue after firing, but is easy to clean with hot soapy water or, even better, good ol' Windex. I've been told the ammonia neutralizes the salts. Manufacturers quit using potassium chlorate many years ago, some sooner than others. Ammo manufactured in the '40's and '50's would be suspect, but newer ammo should be okay. I'm sure others will have more detailed input.

The important thing to remember when firing corrosive ammo is that you need to clean as soon as possible after firing. If you leave it dirty for a couple days, you might find lots of rust on everything. :uhoh:

December 28, 2006, 01:42 PM
I believe if you shoot one cartridge and put the cartridge on a nail and leave it that should tell you if it is corrosive or not. After a day or two, if the nail starts rusting, then it is corrosive.

December 28, 2006, 03:01 PM
The safest method for your gun is to not trust foreign ammo.

With American ammo, there are plenty of sources listing just what ammo was corrosive and what wasn't, so it's easy to ID the corrosive stuff.

With foreign ammo, there is no such info, so the safest method is to treat all the ammo as potentially corrosive and clean the gun with hot, soapy water before using bore solvent.

This doesn't take long, costs nothing, and can save a good firearm.
I've seen foreign ammo the importer listed as Non-corrosive, which WAS corrosive, so don't take chances.

December 28, 2006, 03:19 PM
they are out of bulgarian, i called yesterday. they said they'll be out till the beginning of the year. the consensus seems to be, mil-surp 7.62x54 is ALL corrosive.

not to worry, nothing a little windex doesn't solve :)

sacp- i thought it was mecuric primers that were corrosive?

December 28, 2006, 03:34 PM
ALL surplus ammo is corrosive. No matter what. You can buy some commercial non-corrosive stuff, though. Examples are...Wolf, Winchester, Privi-Partisan, Greek Olympic stuff, and more.

December 28, 2006, 04:15 PM
With a few, well-known exceptions. Swiss GP-11, NATO .308 and 5.56, American .30-06, I think that's about it.

7.62x54R, 8mm, 7.62x39, .303 and all the weird ones should be assumed corrosive, because they all are.

It's not hard to deal with, just grab the windex and clean all metal surfaces before cleaning as normal. Adds a few minutes to the cleaning routine, and you do clean your guns every time, right??

My understanding is that corrosive primers are more stable in long-term (decades) storage, or at least that was the thinking. Giiven that the Russians still fear another German invasion (wonder why...), I'm not surprised they still use corrosive primers.


December 28, 2006, 05:34 PM
Go to a pool & spa store (or Wal-Mart) and buy some pH paper OR a pool terster strip (under $ 4).
Using a bullet puller (inertial hammer) or a pair of house hold pliers, pull the bullet out of the shell and discard.
Take two tumblers (glasses) and add 4 oz water (use bottled water).
Test each glass with pH paper.
Add the powder to ONE glass (should mostly float) and let sit 1 hr.
Place the shell (it has the primer) into the OTHER glass and let sit 1 hr.
Test both glasses with pH paper.
Powder glass should either increase pH by a little or have no change.
Primer/shell glass will be markedly acidic if primer is corrosive, or the pH will be lowered by 1 pH unit (for a non-corrosive primer).

December 28, 2006, 10:54 PM
Pull the bullet, EMPTY THE POWDER OUT OF THE CASE, stuff a ball of steel wool in the case, chamber the round and shoot the ball of steel wool into an old towel using only the force of the primer.

Clean the barrel of your firearm as if the round were corrosive.

Keep an eye on the ball of steel wool to see if it rusts. If the primer is corrosive, it will start to show rust quite quickly.

December 28, 2006, 11:03 PM
Surplus 7.62x54r made in Finland, if I'm not mistaken, is/was not corrosive.

But you'll be very hard pressed finding any of that. :scrutiny:

December 29, 2006, 06:52 AM
sacp- i thought it was mecuric primers that were corrosive?

You're right, I just couldn't remember the names of all the different primer compounds that were corrosive. Potassium chlorate was just a common one I could remember off the top of my head. That would be an interesting little research project. Anyone know a source for what priming compounds were used by manufacturers and their history?

Ask and ye shall receive, at least for American manufactured ammo:

December 29, 2006, 08:11 AM
I use a method I saw in an American Gun mag years ago. Get a bit of untreated steel scrap (a big nail would do), PULL THE BULLET AND EMPTY THE POWDER OUT!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Fire the primed case holding the bbl an inch or so away from the steel. Leave outside, come back after a day or so. All of the steel will probably have rust, but where the blast from the primer hit it will be really bad if the primer was corrosive.

I tend to treat all foriegn ammo as corrosive, except Aussie F4 7.62 ammo and yankee stuff. If in doubt, clean it out.

I don't buy any ex il, but pick up some occasionally in trades, etc.

December 29, 2006, 10:48 AM
Since I'm only looking at surplus for plinking as opposed to hunting or defense, I'll just buy assuming that it's all corrosive and base my purchase on the price.

Thanks, all.


December 29, 2006, 11:01 PM
There is nothing wrong with corrosive ammo. Do not be scared of it. Just clean the bore and gas system with hot water first then clean normaly. Takes an extra 5 minutes.

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