Rusty 7.62x39mm Casings

FMJ 911 · Oct 8, 2011

I have about 400 rounds of old "Wolf" brand 7.62x39mm FMJ ammo. It has polymer coated gray casings, and they were stored in an old car for 10 years. they show signs of rust coming through the polymer, and I'd like to know if that's going to become a problem.

Since I fire 50 rounds or so rounds each shooting session, I should eat them up within a few years, but will they last that long? and will they cause any issues with my gun? they seem to work fine in my SKS.

darkminstrel · Oct 9, 2011

Is it a dusting of rust, pitting, or just a rusty tinge to the cases?

FMJ 911 · Oct 9, 2011

It's sorta like "Spots" on the casings, and it has gotten slightly worse in the past few years.

darkminstrel · Oct 10, 2011

Take an empty case and use some Marine Clean to strip away everything; the poly coat, the rust, dirt, oils, etc. Then put it under a strong light. If you see pitting and don't feel comfortable shooting it then you could always sell it away as components and buy a fresh batch. Alternatively you can put it in an air tight container with some silica packets and not worry. Rust needs air to keep spreading, remove the air and you've got a static situation.

Or go out with some friends and your problem would be solved in about an hour

deadshot2 · Oct 10, 2011

Unfortunately rust, once it starts, continues. It becomes a catalyst for the formation of more rust. It's not going to stop, even if you strip, and clean the spots. It will just get worse in time.

This ammo is probably just fine for some sessions "at the pit". Shoot it up and enjoy. It would be a good idea to just replace it with new and this time don't store it in an old car unless the old car is parked somewhere where the humidity stays around 15% all year long.

FMJ 911 · Oct 10, 2011

Well, My Dad bought this ammo when I was only 8 (1999), and he "thought' the best place for it was in the back of the old Porsche, and the Humidity levels have been recorded at 60% or higher, and it sat back there until 2009, but it already showed signs of the rust.

Maybe if I can find the time, I'll try to use it up. I got a Chinese wind-up 75-Round AK drum full of the stuff.

Also do Lacquered casings have better resistance to rust? I have some "Green" Wolf ammo, and it's older than the "gray" ammo, and looks perfect.

deadshot2 · Oct 10, 2011

FMJ 911 said:
Also do Lacquered casings have better resistance to rust? I have some "Green" Wolf ammo, and it's older than the "gray" ammo, and looks perfect.

Both coatings are prone to rust especially if the "membrane" is pierced. Ammo that has bounced around in the manufacturing process can have small, and often unnoticeable, "pinholes" formed where the sharp edges of the other ammo it's tumbling around with hits it.

The only difference in the color of the coatings is the tendency for it to melt and get the cases stuck in the chamber of the weapon. One is supposed to be heat resistant. I don't know exactly which as I avoid any Wolf steel cased ammo, period.

FMJ 911 · Oct 10, 2011

I only use "Wolf" ammo in my AK & SKS because it works. I'm unsure about "Barnul" or "Tulammo", but since I got 1000's of rounds of the "Green" stuff, I will just use it up. Another nice thing, is that it's lead-core Copper jacket. Range safe! and I've never had a ricochet with it. Dad got it when it was "cheap" ($100 per 1,000 round case)

When I get a chance, I'll buy a case or two of the 1970's Yugoslavian Surplus ammo. it's brass cased, and I heard it shoots good. Not to mention it's inexpensive.(18 cents a bullet)