Corrosive primers vs black powder

[Frank46]

Vern, try boiling that breech block in water. Again a universal solvent. Frank

[inuhbad]

BTW, there's no such thing as "neutralizing corrosive salts" (that phrase hasn't yet been used in this thread, but often rears its ugly head in such discussions), and ammonia has no special anticorrosive effects other than being midly basic. Salt has to be removed by flushing with adequate water to remove it completely, and ammonia's use is to remove copper fouling.

That about sums it up...

The salts CANNOT BE NEUTRALIZED!

Where did some people learn chemistry?
Or where did they hear that salts can be neutralized?

Use WATER to WASH the SALTS from the bore!

The only reason Windex is used frequently is because it can remove some of the OILS which sometimes can cover the SALTS, thereby preventing the major component of Windex, which is WATER, from removing the Salts!

ETA: When I finish firing corrosive ammo, I spray some windex in the barrel until it comes running out the front, remove the bolt & spray the bolt down until it's dripping. I wipe down the bolt with a rag, run a dry patch down the barrel, and then go home. When I get home, I strip any wood / stock off the rifle, strip the bolt and other assembled components down, and I give them a warm soapy water bath... Rinse under running water, and towel dry the parts. I'll use some nitro solvents to keep cleaning the bore until it's 100% clean. Then I spray them all down with WD-40 to displace the remaining water from any of the small cracks, or small sub-assemblies of the gun (front sight posts, bolts, fire control / trigger parts, etc.)...

Then I'll use a rag to put some protectant oil coating all over the rifle, reassemble, put on the stock/wood, and put the gun away.

[The Virginian]

What I think people really mean is neutralizing the effects of corrosive priming salts with what ever method they have used. Salt doesn't really react with water, it just becomes liquid in solution that can then be flushed or wiped away.

[coyote hunter]

What I use for any corrosive ammo, or what might be corrosive ammo ( I love it when the milsurp ammo seller advertize their ammo as mildly corrisive..kind'a like being just a little pregnant ) is a 20% mix of water and Balistol in a handy squeeze bottle. One or two patches saturated with this solution, then dry the bore with a dry patch and due to the cleaning agent and mineral oil in the Balistol, put off a through cleaning until your home in front of a good movie. I wipe down the bolt...everything, then clean with what ever you like later. I use a 50/50 mix to clean my blackpowder rifles and clean my milsurps with the Balistol at full strength. I started using the Balistol about 8 yearsd ago, and never had any problems with it.

[Multigunner]

I have a related question,
Would corrosive primers and cordite as used in British military ammo in the early to mid part of the 1900's affect the throat any more than the bore? I have a SMLE with a nice leade/throat but a little pitting about 4 to 8 inches down the bore.Trying to get a grasp on why the throat is better looking than the bore itself.

Cordite contains mineral jelly (5%) which was added specifically to produce a thin hard skin of carbon fouling to prevent cupronickel jacket materials from becoming fuzed to the bore steel at the leade.
Cordite continues to burn as the charge is blown up the bore, experiments with shortened barrels indicated that the strands usually remained intact until completely consumed. So while pressure curve begins to flatten about three inches into bullet travel the gas temperature continues to rise until the strands are consumed. This burned away remaining carbon deposits leaving the skin of carbon attenuated.
Without the baked on skin, which normal cleaning in the field does not remove and even modern carbon cutter cleaners have a problem with, the corrosive salts penetrated fizzures in the bore surface more easily and are trapped deeper in the steel when the heat and pressure drop.

What you see in your bore is the first sign of a process which results in a little understood condition of mid bore erosion, found so far as I can tell only in Enfield .303 rifles that have fired many thousands of rounds of Cordite propelled ammo under combat conditions.
The localized pitting, described as star shaped pits by those who've examined it with bore scopes is in part due to impact of superheated particulates driven by high velocity gases. This micro scopic roughening of the surface increased the trapping of corrosive salts and also increased thermal gas erosion by giving it a foothold. As the siurface becomes roughened turbulence of the high velocity superheated gas increases transfering more heat to the steel.
Cordite gases of combustion contain a higher percentage of CO2 compared to CO of single base powders. The greater molecular weight of the molecules transfers heat more efficiently and transfers kinetic energy to particulates more efficiently.

The glazeboard card over charge wad reduced gas blowby at the throat, otherwise bores were unusuable after aprox 1,500-2,000 rnds. With the card average bore life could be 12,000 rnds.
By comparasion the Mauser could fire 19,000 rnds and maintain a usable level of accuracy. No over the charge wad was used by any cartridge of this class other than the .303, the MVIIz and MK8Z using 3031 powder required no card, but loose bullet to bore fit usually limited the accuracy life of Enfields using those rounds since there was not as much initial shock to bump up the bullet.
The protection provided by the card lasted for only an inch or so of bullet travel.

In the worst examples I've examined the last ten inches of bore can appear new and with no noticable wear, yet from that point back to just in front of the throat the bore is eroded far oversized, with grooves guttered deeply while lands show a bit less loss of material.
Quality of ammunition varied greatly in wartime and apparently some manufacturers produced Cordite with additives that reduced the erosive effects.
Rifles from WW1 with original barrels are most likely to show this pattern of erosion, more likely due to mass rapid fire than other factors. WW2 saw much less reliance on mass rapid firing so bores had time to cool a bit and fewer rounds would be fired between cleanings.

Since the vast majority of rifles with bores visibly eroded would have been rebarreled or downgraded to Drill Purpose only most Enfield owners have never encountered this level of erosion, and you have to see it to believe it.

Interestingly modern stainless steel owes its existence to experiments aimed at creating an alloy that would resist Cordite erosion. Lithgow produced a few stainless barreled No.1 rifles, the serial number starting with an X IIRC.

[Pirate69]

There have been lots of discussions on the effectiveness of ammonia solutions preventing bore corrosion. I agree that amonia solutions do not neutralize corrosive salts. But it does change the chemical species that contains the chloride and makes the chloride more soluble in water. The fail-safe approach is the more hot, soapy water the better; whether it contains ammonia or not. The following is my comments in a similar thread in 2007:

"The water will put the salts into solution. If you spray distilled water and allow it to dry, the salts are redeposited, without any change in their chemistry. However, if you dissolve the salts in a solution that also contains ammonia, the following reaction takes place:

NH4OH + KCl = NH4Cl + KOH

The water acts as the solvent that allows the ammonia and the potassium salts to come together and react. The amount of ammonia in the solution will impact how much of the salts that are consumed in the reaction. So you need a larger volume of low concentration solution or a smaller amount of a higher concentration solution. I have found that that the cheap cleaning solutions containing higher concentrations of ammonia work very well. I have also found that a good scrubbing with lots of hot, soapy water will put everything into solution and the salts are greatly diluted and flushed away with the shear volume of the water used. Either way, especially if you are dealing with black powder, a good cleaning will help to prevent the corrosion.

If you are using a solution with a low concentration of ammonia, then you may not see any appreciable effect over just using a generous amount of hot, soapy water. However, the chemistry is there and if you have enough ammonia to react with the salts, you will get an increase in salt removal, all things relative.

To illustrate my point, consider using only distilled water sprayed into the barrel. The potassium chloride remains as potassiun chloride and is unreacted. The solubility of KCl is 24 grams per 100 grams of cold water and 57 grams per 100 grams of hot water. If you use an ammonia solution, again saying a solution with enough NH3 to be effective, you will convert the KCl to NH4Cl. The solubility of NH4Cl is 30 grams per 100 grams of cold water and 76 grams per 100 grams of hot water. With the use of ammonia, you have converted the KCl to NH4Cl and increased the solubility of the chloride ion by approximately 25% in cold water and approximately 37% in hot water. So in a water limited situation, such as a spray down a barrel, the higher solubility will remove more chlorides.

In a situation where you are using a lot of hot soapy water, you will also get the chlorides out, whether you use ammonia or not. In a case where a shot of cold distilled water and a shot of cold Windex is sprayed down a barrel, the Windex will put more of the chlorides into solution. How much depends on the volume of the spays and the concentration of the ammonia in the sprays.

I think the one thing we all can agree on is that the corrosive salts must be removed to prevent rust. And all must be removed, not just part of the salts. For corrosion to occur, the barrel's surface must be dampened by a water solution that can conduct an electric current. The moisture can come from humidity. If salts are present, corrosion rates can be increased. Salts absorb moisture from the air. This means corrosion can occur at lower relative humidity levels. The salts will increase the ability of water to carry current and thus the corrosion rate will increase. Salts gradually begins to absorb water and form a corrosive concentrated chloride solution when critical humidity and temperaure combinations are reached. It is important to note that this is different for different salt species. At the point that the critical humidity/temperature condition is met, corrosion is the greatest for that salt species because the corrosive solution in in its highest concentration. This is important to note because inadequate salts removal can still lead to corrosion.

I guess the important thing is to do what is necessary to remove all the salts. That may be large volumes of hot soapy water or the same with ammonia to convert the KCl to a less corrosive salt, with a higher solubility factor. Either one can do the job, but, all things being equal, the use of the ammonia will give a higher solubility of the salts and the conversion to a less corrosive form. I like to hedge my bets when possible."

[improman]

pull the bullets .dump them into boxer primed brass ..reload/re-use..not to worry n wonder

[Lead Fred]

When I was shooting 8mm mausers, Id swab the barrel with ammonia to neutralize the primer residue, then clean normaly like any other firearm.

[.22-10-45]

Hello rugerman1, I too have found this bore wear forward of leade. I was fire-lapping a Krag, I found leade tight & 6 or 8 inches forward, bore was "loose". It seems the early smokeless
generated peak pressure in this area...only a few .0001's . The fire-lapping uniformed the bore.

[Doug Bowser]

Use Murphy's Oil Soap concentrate. 1/4 cup MOS to 1 gallon water. I have never had a problem with corrosive primers or BP fouling using this formula. swab the bore and dry it out. Clean the bolt face. Then clean with Hoppe's #9 with a bronze brush.

Doug

[badbob454]

Not so much the primers as the powder. Cordite has a high burning temperature and is quite erosive to barrel throats.

Rocklock that's what i was thinking too cordite is much hotter and burns out the bore faster than nitrocellulose // i also heard in error, ammonia neutralizes salt. nice to know why my mosin keeps rusting .... gotta flush it with water first , then oil it

[Doug Bowser]

BadBogerman,

Th best solvent for black powder and corrosive priming is, 1/4 cup Murphy's Oil Concentrate in 1 Gallon of water. Swab the bore and let it set 1/2 hour. Dry the bore and clean the normal way with Hoppe's #9. Check the bore after 3 days and repeat reatment if the bore looks dusty. I have never had to repeat the treatment .

Doug

[Springfield]

I'm with Doug, except I like BreakFree beter than Hoppes. In my experience it is a better rust preventer. Just make sure you put SOMETHING on there after the water bath, although the Murphy's Oil Soap seems to help all by itself.

[omgb]

I shoot a lot of BP cartridge and shotgun during the course of a year. I clean with MOS and water, dry and follow with RemOil. Nothing special. In over 20 years of this I've had zero corrosion problems.


Ditto with Korean and Commie surplus ammo. Hot water, MOS and Remoil...no problems at all.

[flounderman]

if you shoot a corrosive primer, the way the army handled it was to remove the bolt, stick the muzzle in a pan of hot or boiling water and run a patch up and down the bore, sucking the hot water up the barrel. the heat will dry the barrel and you oil it afterwards. we received some corrosive dcm ammunition once and had to do this. I bought 1000 older winchester primers once that turned out to be corrosive altho they didn't say they were. ruined a barrel I had cleaned and oiled and didn't use for a while. oil doesn't protect from corrosive primers.

[The Virginian]

There are lots of good milsurp firearms that have been damaged or even ruined by the improper cleaning after shooting this corrosive ammunition. Prior to about 1956, US Military ammunition contained corrosive primers that are potassium chlorate based that when fired produces a corrosive salt that is spread through the barrel, onto the muzzle and sights and into the bolt and action of a firearm. Many sources of surplus Soviet Block, Chinese, Eastern European, African, Indian, Middle Eastern and allied WWII and earlier ammunition also has been loaded with corrosive primers. It is a safe assumption that if you are not sure of the type of primers used in that economical case of Egyptian 9mm Luger, that to be on the safe side assume they have corrosive primers. Also do not assume since the seller billed the ammo as "mildly corrosive" that it is not a big deal as it is as realistic as being " mildly pregnant." There is no such thing as "mildly corrosive" as the ammo is either primed with corrosive primers or it is not! Treat ammo that has the word corrosive in it as simply corrosive primed ammo.... period. The process of shooting corrosive ammunition in your firearm is perfectly normal for many milsurp guns as it was done for decades and it was believed that the corrosive primers were more stable than early non-corrosive primers. Most US and European ammunition made today uses a non corrosive primer that is lead based and can be cleaned up in the usual fashion with a good bore solvent and general solvent followed by wiping the parts and re-oliling them. This IS NOT the case when shooting corrosive ammunition in your firearm as there is a spraying and layering of corrosive salts that are not removed by using typical bore solvent like Hoppe's #9 and the corrosive salt will remain to hydroscopically pull moisture from the air to start to rust your valued firearm even when oiled. The good news is corrosive salts can be removed with very simple methods and making sure that the firearm is cleaned reasonably soon after a range session involving the firing of corrosive primed ammunition will prevent it from developing rust. Do not let your gun sit with corrosive primed ammunition especially in a moist environment for more than a day and even that is pushing it in my opinion.

One of the tried and true methods of cleaning away corrosive primers involves using two very available household items.......hot water and diswashing soap like Dawn Liquid....no magic, no spells or voodoo dolls are needed! LOL!

After a shooting session using your economical surplus corrosive ammo, remove the bolt and magazine (if the gun has one) . Get a bucket, fill it with very hot soapy water and drop the bolt and magazine into the hot soapy water. Next take a tooth brush and scrub vigorously in all the nooks and crannies paying particular attention to the bolt face and on the feed lips and follower if there is a magazine. After the part has been scrubbed and is clean, rinse in clean hot water and dry with compressed air or something like gunscrubber or brake cleaner (non-chlorinated formula) and set aside. If shooting a semi-auto, disassemble and clean the gas piston and any parts that are using the gas from the fired case to work the action and clean as described for the bolt. Next run two very soapy patches wetted with hot water through the bore and chamber(s) of the firearm. Next run a bronze brush wetted with more soapy hot water through the bore/barrel 2-3 times. Get some very hot water and a funnel with an attached flexible piece of appropriately sized rubber tubing at the end pour the clean hot water from the breach end through to the muzzle and into an other bucket. I like to then run 2 more soapy hot water patches down the bore again and rinse once more. To ensure all moisture is gone I then saturate a patch with acetone, gunscrubber or break cleaner and run it down the bore. Between the the drying of the break cleaner and heat from the hot water the bore dries very quickly. I will also try to wipe down with soapy water and then hot water on patches, any areas that may have been exposed to the corrosive salts like the front sight, then spray them with acetone or gunscrubber to dry. After I am satisfied that everything has been scrubbed, rinsed with hot water and dried off I then clean and oil the gun and its respective parts as I normally would if not shooting corrosive primers. I use a good bore solvent on the bore and Ed's Red home made gun solvent that is made of equal parts of ATF (Automatic Transmission Fluid), K1 Deodorized Kerosene and mineral spirits on everything else. This is just my chosen gun solvent, but any of the commerical solvents like Hoppe's #9, Shooters Choice etc will work fine. Any good gun oil will work fine but my favorite when oiling after shooting corrosive primers is CorrosionX that is designed for marine and aviation environments. When cleaning the bore make sure that all the final passes of your drying patches come out clean and if not, clean again until they are squeaky clean. Lastly, use a good gun oil to lightly oil the bolt, magazine and bore then wipe down the gun with a clean oiled rag or patch before putting it away. It is also prudent to check your gun 1-3 days after shooting corrosive ammunition and cleaning it to make sure you didn't miss anything and to ensure no rust has formed. If for some reason it has started to get surface rust after that time, repeat the cleaning process from step one and monitor the firearm for any signs of rust. Typcially after this second cleaning you should not have a problem and seldom if ever if the first cleaning was done properly. Shooting corrosive ammo requires a few more cleaning steps to keep your gun free of rust, but considering the savings in surplus ammunition it can be well worth the work.

[Grapeshot]

Just a suggestion; Ballistol works well when cleaning bores fired with corrosive ammo. U.S. Military Surplus Rifle Bore Cleaner was a great cleaner of M1's and '03 Springfield's that were fired with corrosive ammo back during WW2 and Korean War.

[gunauthor]

I have used Hoppe's #9 for many years and many rounds of corrosive ammunition and had no rust problems. I buy the stuff by the gallon......

[bigjake]

Multigunner and pirate69, In the 7.62x54r ammo from Russia or Europe, the primers are corrosive, but is the powder corrosive?

[aap2]

Great old thread with much good info. I'm not an expert but just a shooter who has fired tons of old and recent surplus ammo without ever rusting a bore despite the ammo having corrosive primers..smokeless powder is not corrosive (as far as I know) but some primers are.. I used to "test" lots of suspected "corrosive primed" surplus ammo by taking a sample round, pulling the bullet and dumping the powder and firing the primed case at a razor blade degreased by dipping in alcohol and letting it dry. Corrosive primers will rust the razor blade badly overnight. If it's corrosive, no problem if the gun is properly cleaned. No voodoo here: corrosive primer residue is soluble in plain old hot water. Adding some Dawn detergent makes a super cleaner. After firing my first real rifle (Springfield 1903) with known corrosive ammo from WW1 (all I could afford as a kid), I was taught to remove the bolt and stick the muzzle into a bucket of hot soapy water and pump the water thru the bore with a rod and patch until spotless. Then used a small teakettle to pour hot water thru the action, dry patch then follow with oiled patches. Did this for many, many years and 40 years later the bore is still pristine. Plain water is good, hot water with soap and rinse in hot water is better then dry patch and oil. Any "miracle" solvent for corrosive primer residue (like military rifle bore cleaner, windex etc only work because they contain lots of water). Pretty much the same story for real blackpowder...the residue is corrosive because it contains KNO3 (potassium nitrate) which is also soluble in plain old water. Same treatment. Today at 60+ years old I treat ANY surplus ammo as potentially corrosive (despite claims by the seller) and clean as stated above. No rusted bores, ever. Your mileage may vary, just telling what has worked for me. Hot water plus Dawn is the best cleaner for corrosive primers IMHO and we all have it at home.