Corrosive Ammunition Issues

This material is independent of the official LPRGC CMP site

Last Updated May 21, 2003

General Corrosive Ammo Issues
(and Determining if your Ammo is Corrosive):

Well, I was kind of hoping for something beyond "lab" testing every lot of ammo.

In short, there is no substitute for a lab test. The test for presence of corrosive priming is best done by professionals due to the hazards involved in the actual test and the absolute requirement for accuracy in the test. See below for a "home" test that is available for the home user. The test was developed by a friend who works in a medical lab that is familiar with test procedures, he graciously shared it with me one day, he is a shooter also.

Has it been people's experience that the bulk ammo purchased at gun-shows that is advertised as non-corrosive actually is as stated?

You bet your a$$ some of it is corrosive. Intentional mislabeling has been a hallmark of the shifty ammo dealer for years. My favorite? "Slightly corrosive" or "Mildly corrosive" BWHAHAHAHAHAHAHAA!

There were two types of primers available for the majority of the period we are talking about (World War 1 to about present). Sodium Petrochlorate (corrosive) and non-corrosive (usually lead stypnate).


Either it is a corrosively based priming compound or it isn't. Either you are dead or you ain't. Either your gal is pregnant or she isn't. Black & White issue, no gray. Ammo is corrosively primed or it isn't. No in-between. No mildly. No almost.

The solution to properly clean within 8 hours every time doesn't quite make it in that I understand you need extra cleaning steps for corrosive ammo that one normally wouldn't do.

Such as? Whether I use corrosive or non-corrosive ammo, I clean the same way. In gas guns I clean each part that was hit with the gas.

Is it true that the corrosive .30-06 one might encounter would normally be old ammo, or is there stuff out there from the last few decades that is corrosive?

Barnaul Arsenal in Russia is still producing today 5.56, 5.45, and 9mmMak using corrosive primers. TODAY. But, they use non-corrosive priming on commercial ammo for export. We hope. There is no way to tell with foreign ammo by simply looking at it. A test is the only absolute sure way.

Related to that, is the problem CMP ammo old stuff? Is this the same ammo one can buy for $84 a load, or is the armory stuff obtained through other means. I was all set to buy some but now I'm nervous.

You want my advice? (worth what you paid for it) Whether or not ammo is corrosive should not be your buy factor, but price should be. If its cheap enough, buy it, if not, don't. More will come in later. Today we are SWAMPED with .308. Four years ago you couldn't find it anywhere. I am buying as much of the Turkish 8MM as I can afford. You can't usually buy a 8MM *projectile* for what they are selling a loaded round for.

(Rant mode on:)

After being in the business for years, I am convinced of the following:

Anyone ever wonder why virtually *ALL* ammo sells for between .14 and .22 cents a round for Military Surplus???

Virtually all 30.06 surplus that comes in the country sells for about .15/.16/.17 cents a round. Ammo from Austria. Ammo from Venezuela. Ammo from Greece. Ammo from every corner of the world.

And it all arrives here with a few pennies of each other? Hmmmmmmm... I wonder if there is price fixing in the surplus market... wink wink.

(Rant mode off)

Home test for corrosive ammo:

You will need to have FOUR controls for an accurate test:

  1. Positive Control - A known corrosively primed round (I use 1940 dated 7.62x54R)
  2. Negative Control - A known non-corrosively primed round (I use Remington .22LR)
  3. Control - A clean piece of degreased metal
  4. Test Control - The suspect round

First, pull all bullets, dump powder and discard. We want THREE primed empty cartridge cases here folks. Be safe.

Clean and degrease FOUR pieces of steel. I use old unusable M-16 Stripper clip housings (the steel piece, not the brass insert). I prep them by briefly touching the steel to a grind wheel to expose raw steel (this gets rid of the Parkerizing). Label each piece with a 1,2,3, & 4 with a marking (sharpie/permanent) pen.

Label each empty cartridge case with a 1, 2, or 3. Fire each cartridge case onto its corresponding numbered piece of steel. The fourth piece is placed with the others as a ambient temperature/humidity control. Place all four pieces in a shallow Tupperware container on top of your fridge near the back (this is an ideal warm humid place) UNCOVERED for 4-5 days.

Optional: If you are in a very dry climate, place a shot glass of water in the Tupperware to provide a small region of humidity. Unnecessary anywhere except desert regions or very cold dry climates.

After 4-5 days inspect the pieces of steel. Compare the suspect steel to the CONTROL piece (the one piece you didn't fire a cartridge on). Is it rusted more or less? Does it have strange colors? If yes, compare it to the POSITIVE control. Equal? It's corrosive. Does it look like the NEGATIVE control? Then it is likely that it is non-corrosive. But, still check after you fire the ammo for fast growing crud. The difference will be obvious, as a corrosively primed round will grow rust and strange stuff almost overnight. Sometimes, the Negative control piece will exhibit almost zero rust, due to the sealing effect the priming compound has on the steel. This is especially true if you use a .22 pistol to fire the empty cartridge, like I do.

This is not a perfect test, but it is one you can use at home with great accuracy. I have used it for over 10 years, for hundreds of suspect rounds, and I was wrong ONCE (verified by lab test). So, my success rate is still over 99.9% with this test.

Freely posted in the public domain. No copyright.

Tom Dugas
Houston TX

Posted on this website with explicit permission of author on May 31, 2000.

Cleaning Instructions After Using Corrosive Ammo:

The correct way is to use boiling hot soapy water. A one or two gallon pail works well. Field strip, put loose parts in pail to soak. Immerse receiver in solution and scrub the bore and chamber with a brush and solid rod, using a muzzle protector. Remove the gas plug, immerse the gas cylinder and muzzle (but not the handguard) and swab the cylinder bore with a brush. Repeat in boiling hot 'rinse' water with a few drops of oil on the surface. Clean the residue from the small parts and the recessses of the receiver with an old toothbrush. Use Hot water and latex gloves to protect your hands. The hot water evaporates quickly, and WD-40 can be used to displace moisture from the rear sight and the bolt extractor without disassembly. Swab the bore with an oily patch, then use it to go over all parts. Grease and reassemble.

Resourceful GI's could bathe, shave, clean the M1 and their socks in a helmet of boiling water.

[Memorial Day is] A good day to remember my dad, my uncles and their buddies and the war stories they told in those post WW2 years before TV took over as family entertainment.....

hoo rah!

Whitehorse, Yukon, Canada

Posted on this website with explicit permission of author on June 1, 2000.

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