What's the deal with corrosive ammo?
I have Mosin Nagant that I've been shooting for a couple of years, mostly some corrosive surplus ammo that I picked up from aimsurplus. I read a tip on a MN board to just run a swatch with a few drops of diluted ammonia through the barrel if I wasn't going to clean it right away. Well, I haven't exactly been 'good' about cleaning it after each use, or even doing the ammonia trick, but each time I clean it up - it still seems to be a nice bright bore. So, what's the deal with corrosive ammo? From the way some folks talk it'll eat through the barrel in no time.[?]
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For some unexplained reason people seem to have the idea that ammonia is the quick fix for corrosive ammo. Ammonia works well on copper fouling but what you really need it some sort of water based cleaning agent...like hot soapy water. The problem is that older cartridge primers use potassium chloride (salt) andthese salts get spread when you fire the rifle and they quickly attract water and water leads to rust. The trick here is to get the upper hand by using water as a friend to clear away the salts: Just use plenty of hot water to disolve and wash away the salts and then clean, dry, and oil the metal. Plain bore cleaners like Hoppes will not work on corrosive ammo so you either need to use plain water or some of the old water based GI bore cleaners. If you live in a dry climate you can last a while before the corrosion starts but if you are in humid conditions the rust will form quickly and you should not waste any time cleaning your rifle.
"Nothing can ever be made 'idiot proof' because idiots are simply too clever"!
Mark T. Christian0 -
Older ammo used a mecuric-based priming compound. The residue from it absorbs humidity and can rot the bore out of a gun. The ammonia dissolves the residue salts easily. If'n you use milsurp ammo, it is a good policy to do a throrough cleaning afterwards. I've used milsurp ammo for years and never had any problems, but I am meticulous about cleaning my guns after use.
Love them Beavers
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Mark, I might be wrong on this, but I thought the potassium chloride was an agent in the gunpowder which accelerates the corrosion because of its properties as an oxidizer.
Love them Beavers0 -
I bet you live in a dry climate.
I am in the mountains of N. Carolina, very humid. I CLEANED my Finnish Mosin after firing corrosive, in fact I used ammonia.
A week later I ran a patch down the bore, and it was covered with red rust.
This is a rare $350 Finnish Mosin that a lot of the collectors would not shoot in the first place, I was shocked to say the least.
The only way you are getting away with sloppy cleaning habits is if you are in a low humidity environment.
Plus, some corrosive ammo is more corrosive than others.
I agree with Mark, use hot soapy water. In WW2 the Marines would heat up a pot of water, and put some soap in it. Remove the bolt. Put a patch on the rod, put the muzzle in the water and give the bore 10 or 15 strokes. Bye bye to corrosive salts. Then, clean as usual.
This is the procedure that I now use. Especially since I dripped some diluted ammonia on the stock and it ate the finish off. Ammonia will also eat up the bluing. I know lots of people swear by ammonia, I swear at it.0 -
Here's what is happening chemically.
For non-mercuric corrosive primers the trouble maker is potassium chlorate. Potassium chlorate (KCLO3)is a strong oxidizer and provides oxygen to the reaction when the primer ignites. This means the primer agent can ignite without the presence of atmospheric oxygen since the primer agent carries its own oxygen. Something like rocket fuel. Oxygen can be a very reactive element. After primer ignition the oxygen of course is now used and the potassium chorate is now potassium chloride (KCL) a type of salt. Please note the lose of the oxygen atoms in the formulas.
If you ever look at a salt substitute at the grocery store you will probably see potassium chloride as one of the main ingredients. Don't get this confused with calcium chloride which is used in huge quantities to melt ice and snow on streets when temperatures are below freezing.
Anyway many of the salts including potassium chloride are extremely soluble in water but are not soluble in oil or solvent. Therefore, if you try to clean corrisive ammunition residue with a solvent or oil all that happens is the salt is applied in a nice uniform layer on the inside of the barrel and maybe spread to the action.
Since water is what solubilizes salt the use of water on corrosive ammunition residue is much better and will instantly dissolve and wash the salt out of the barrel. A little soap acts as a surfacant to lift dirt and carbon out of the barrel with water.
"If I don't see you nomore on this world, I'll meet you on the next one, and don't be late!" - Jimi Hendrix0 -
Mercury weakens brass cartridge cases but has no ill effects on steels used in firearms. So called "ammonia doping" was a precedure used between the wars to eliminate copper fouling and invloved the use of a specific blending of the ammonia dope and was not simply pouring straight ammonia into the barrel as it will corrode steel upon contact if the steel is also exposed to air. In the old days the bore was plugged, a rubber "nipple" was placed over the muzzel which extended an inch or two above it. The barrel was then filled with the dope slowly through a funnel so that the fluid level extended above the muzzel itself which meant that the bore was not exposed to air and ammonia at the same time. The maximum exposure time for dopping the bore was thirty minutes when using a fresh solution (old dope was less effective and even more harmful on steel so it was not reused) and any time beyond that risked severe damage to the barrel. Some where along the line the old issues of copper fouling, primers containing mercury, and corrosive primers have all become jumbled together but in point of fact each is a totally seperate issue and was treated with differing remedies. I am sorry about your Finnish Nagant Allen because I know you are a serious collector of military bolt action rifles. Ammonia can be deadly to gun steel if misused. By the early 1930's there was a change in the compostion of bullet jackets which all but eliminated the issue of copper fouling and ammonia dopping was then prohibited from use on firearms in US service by our military.
"Nothing can ever be made 'idiot proof' because idiots are simply too clever"!
Mark T. Christian0 -
Indeed potassium chlorate compound in the primers, and the resultant salt potassium chloride after shooting, is the culprit. Indeed this salt is water soluble, and should be removed with a water-based cleaner ASAP after shooting. The salt residues are hygroscopic, i.e. they attract and absorb moisture from the air. Humid climates, more moisture faster. Water plus salt plus bare steel equals rapid oxidation (rusting). Rough bores like many older milsurp rifles, which didn't get cleaned often enough or quickly enough, have the problem increased by heavy fouling accumulations, including metal fouling. Extensive cleaning may be necessary in a rough bore, as salt-compound residues are present beneath the fouling. I shoot a lot of milsurp, especially 7.62x54R in various Mosin rifles. Some clean up easily and quickly, others take a lot of time and effort, depending on the smoothness of the bore.
As far as I know, most if not all of the Soviet-bloc ammo used potassium chlorate-compound priming, because of long-term stability and reliability. I treat it all as if corrosive, to be sure.0 -
Thanks for your concern about my Finn, Mark.
It is a M39 SkY, mint condition with stock cartouche. Any collector would love to have it, and most would not shoot it.
If I own it, I shoot it. I got some "pointers" on cleaning with ammonia from another web site, which has proven to otherwise be very reliable, in fact, it was from that web site that I got the gun.
I was using diluted ammonia, 2 parts water to 1 part ammonia, something like that.
When I got that patch covered with rust out of the bore I nearly fainted. I ran 7 or 8 more patches down there, till they came out clean. Then, I got out the bore brush, Hoppes etc. To my vast relief I wound up with a perfect mirror bore, you cannot tell that it was ever damaged.
I damaged a 2 inch by 1/2 inch strip along the handguard with that damned ammonia mix. Thanks to another internet tip, I put some Olde English furniture polish on it, and that damage disappeared also.
I have not caused any damage with hot soapy water and gun oil. Good enough for US Marines, good enough for me.0 -
This has been a super discussion of the myriad issues involving corrosive primed ammunition - even this ammo guy learned some new things! Thank you, gentlemen.
But one thing may have been overlooked? Aren't the bores of the Soviet rifles chromed to minimize these problems? Jb did not ID the origin of his rifle, but could this not be the reason he has had no problems, rather than his climate?
FWIW, I would not consider using ammonia for the cleaning process. For corrosive salts, hot water has worked for more than 100 years. For copper fouling, there are great commercial products. The results are not likely to vary (allen, that's not a slam).
"There is nothing lower than the human race - except the french." (Mark Twain)0 -
Pour salt in ammonia. Then pour some in hot soapy water. See which dissolves more salt easier. The water. End of discussion. Dry, then clean with regular cleaner.
"...hit your enemy in the belly, and kick him when he is down, and boil his prisoners in oil- if you take any- and torture his women and children. Then people will keep clear of you..." -Admiral of the Fleet Lord Fisher, speaking at the Hague Peace Conf0 -
My WWII and earlier Mosins and Finn 39's don't have a chromed bore. Later SKS's and AK's I have and have had do have chromed bores. The chrome helps a lot! 0 -
Mine is from 1955, and I believe Romanian 0
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