Should I be alarmed?

7

7jinxed7

New member
This is a M1A rifle that I purchased new. I've had it for awhile now. I shot some ammo over a year ago that I recently saw online that it is claimed to be corrosive. It was Czech .308 1983 with two circles on it. I shot about 30 rounds of it over a year ago and the rifle has been put up since I cleaned it. I had no idea at the time that it was corrosive. At the time I just used the typical Hoppe's #9 ,a copper fouling remover,brush,etc. I didn't have a chamber brush at the time. I cain't really see anything wrong other than this in the chamber and the mag release is a little red looking but I can't see anything else. Should I be alarmed about this?

I still have some of the ammo. I noticed their is a red rusty color all inside the casing.

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This photo was taken today.
 
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Make sure you clean with hot water, the "corrosive" residues are salts and don't dissolve well in Hope's etc. The main damage potential is in the throat area, not the chamber.
 
There is some areas in the photo of your chamber that look like it could be fine rust (There is no such thing as, "surface rust", if it is rust, it has caused at least microscopic pits in the steel.) If it is indeed rust, depending how deep the pits are, there could be some extraction problems.
Note to other posters: His OP did not ask about proper cleaning when firing corrosive ammo, his OP was if he should be concerned about the condition of his rifle chamber.
 
Thats right Dahermit. I fired corrosive ammo unknowingly. Cleaned as i normally would non-corrosive ammo put it up for a year or so and now I have this. :eek: I may see if I can find a local smith and see if they can do something.
 
7jinxed7,

That pair of circles on opposite sides of the case is Sellier & Bellot's headstamp. I've seen claims both that it is and that it is not corrosive. I suspect it may be, and have written S&B to get a definitive reply, if their records tell the tale, but as yet have no answer. Keep in mind they won't initiate corrosion until the humidity is above around 70%. Hatcher's Notebook has the exact range. The specific relative humidity at which the potassium chloride starts rust changes with temperature. If you don't keep the gun in a damp environment, you may not see it.

I got a case of the 1060 rounds of that S&B ball with the 1982 headstamp about 20 years ago. I put them through my M1A with no corrosion symptoms. I was cleaning with Sweet's 7.62 at the time, which includes water and ammonia, so it would remove potassium chloride deposits and neutralize any acids. Today I strongly recommend Bore Tech Eliminator, as it is water-based, non-toxic, non-ammonia, odorless, and it removes copper faster than about anything else (I don't even try to use brass rods or jags with it as they are attacked rapidly and turn the patch blue). It also quickly gets carbon out, so for high power rifle not shooting lead, it covers the bases. I've tried just about every bore cleaner ever made, and this stuff is just a better mouse trap for jacketed bullet shooting. Read the reviews on Midway and you'll discover much the same observation from others.

That S&B surplus ammo is lousy stuff. It is labeled .308W on the head instead of 7.62, so it isn't military in the normal way that's done. I suspect the 143 grain bullet is a big part of the problem, but haven't reloaded any to prove it. But I also suspect this ammo was stored in very poor conditions because I have some cases that have corroded through the brass from the neck to the bullet. Of the portion of the ammo I have that looks good on the outside, about one in 20 rounds fire either too weakly to cycle the M1A, or just barely cycle it. Pulling some of the cartridges down, the powder seems to be almost glued in place and has to be removed with a scraper stick. There is no bullet sealant in these rounds, and I suspect moisture damage to the powder.

Smokeless powder makes a reddish dust if it breaks down far enough to consume all of the antacid carbonate they mix in. That reddish coloring is from acid evolving. The acid could etch the zinc out of brass, leaving it reddish looking on the inside of the case; that, or, you've got some of the red dust planted there.

The acid could initiate your surface rust, if the temperature of combustion didn't destroy it. But a lot of things can bring that about. I've even found rust in barrel blanks before. All it takes is humidity and not enough of an effective corrosion inhibitor.

I would pull enough of the cartridges to check conditions inside the cases. If you've got powder deteriorating it will likely smell acrid and you may see the red dust on it. Such rounds should be pulled and the powder dumped, at least. If the cases look etched, they should be tossed, too. If you want to try to make the bullets shoot, you probably can.

I would take a larger caliber bore mop and get the chamber and bore wet with Kroil or PB Blaster and let it sit for a day then run patches through and rub the chamber or other red spots off with a patch that has JB Bore paste or Brasso or tumbling media polish on it. In the M1A, you can run a cleaning rod in and then screw the bore mop on. As an alternative, Hoppe's used to make a chamber brush rod with a flexible Nylon shaft that I've used in Garands and M1A's a lot. I hope they still make it. In any event, in a couple of days the rust will be loose from the penetrating oil and you can polish it out. If you want to, you can layer patches onto an undersize brush and polish the chamber further with Flitz.

Contrary to popular misconception, a polished chamber does not dramatically increase bolt thrust, but rather, by requiring a greater length of brass to keep holding onto the case for the head to stretch back, it actually distributes the pressure ring over greater case length, making it much less thin and less likely to initiate a separation. (Varmint Al's web site has an animated FEA model of the .243 Winchester showing how the brass in the polished chamber stretches the case head back without getting a well defined pressure ring.)
 
Wow you seem to know what your talking about. I appreciate the info. I'll try the Kroil and polish and see how it does.

I opened four casings so far and all have a redish corrosion looking substance on the casing walls. It does fall out it' s stuck in there. Some of the powder is stuck to it as well. The powder really didn't have a odor to it. Didn't look discolored or abnormal to me. Wasn't clumped at all. But the casing walls looked down right nasty. I will not fire any more of it, but I will save a little in case a smith wants to look at it.

I red online that you can fire a empty casing onto a raw piece of metal and wait to see if it corrodes. I don't know how accurate this is or if it's true or not. I attempted it just for kicks. It's been 24 hours and it's in my garage humidity is about 33% currently and about 80 degrees,still nothing as of yet.I would like to try it again when humidity is higher.

You mentioned using a flexible nylon shaft,I used a Glock plastic rod with great success on my mini14 the other day.
 
Yes, 7jinxed7, Unclenick does seem to know what he's talking about. He's an engineer with an above-average understanding of chemistry mixed in with a passion for shooting, research and teaching. He's one of several very knowledgeable folks around here.
 
Thank you kindly sir. You don't seem to miss many tricks yourself these days.

I have now heard back from Sellier & Bellot. The response was they aren't sure. They didn't believe it was likely cases with the double circles would be corrosively primed, but he said that back in those "days of the iron curtain" they made a lot of contract ammo to different specs for different countries, so without knowing who the ammunition was shipped to originally, he cannot be certain. He is aware a lot of this ammo was later surplussed out by the countries who ordered it originally. Obviously, S&B had no control in the matter and cannot warrant it one way or the other. They can only guarantee all their current production is either non-corrosively primed or is, for some gallery pistol ammunition, has heavy metal-free non-toxic priming.

I still don't know why a military contract round would be stamped .308 instead of 7.62, but from the bullet construction, that's what it is. I went ahead and etched the copper off a pulled bullet. They are indeed plated soft steel jackets (why a magnet attracts them). I imagine steel, being less malleable than gilding metal, is harder to get the same jacket wall uniformity from. That may account for the accuracy issues I had with it?

If the red dust you see is in your pull-down cases, the powder is definitely deteriorating, smell or no. If you don't have one already, I would get a Hornady Cam-lock (sp?) bullet pullet and pull them all down (it's way faster and easier than inertial pullers or the turn-to-tighten collet pullers. Use the old powder for lawn fertilizer. If the primers turn out to be OK, you can work a load up with them that functions better.

BTW, since the salt corrosion requires humidity to appear, I suggest you put the steel plate in a closed jar with a little cup of water in the jar with it. That will hit 100% RH pretty fast and let you see if corrosion is going to occur? Don't forget to clean the gun with a water-based cleaner followed up by Ed's Red or some preservative cleaner the next day. Hatcher says the old rule for corrosive primers was to clean immediately after shooting and again the next day. He used the old arsenal equivalent to Ed's Red, and says he never had a problem with rust. Ed's Red is good at getting carbon out, too (probably where most of the salt hides). It's main limitation is it includes no copper remover.
 
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