cleaning brass fouling

S

stagpanther

New member
Friend has shot brass solid dangerous game bullets through his rifle and I'm having a devil of a time clearing it from the bore--any suggestions? I've used both paste abrasives and solvents, but the brass remains in stubborn patches near the muzzle.
 
The same chelating bore cleaners that eat copper fast will strip it out of brass. Bore Tech Cu++ acts so fast that I can't use brass jags with it because they start turning the patch blue in the time it takes to push the patch through the bore.

I put some Cu++ in a traveler's pump sprayer from Walmart and just pump about three spritzes in from the breech and watch it run toward the muzzle. Then put stoppers in and let it sit for an hour and patch it out using a plastic jag or a nickel-plated one. (Bore Tech makes a special alloy jag called a Proof Positive jag that won't react with it, but we aren't scrubbing here, so plastic will do well enough). Repeat until nothing else comes out.

Another good one that is even more aggressive than Cu++ is KG-12. It just has the drawback that it doesn't turn blue or gree to let you know it is done. It just sort of gets a deeper orange color.

Depending on the powder used, guns can layer carbon and metal fouling, so if the process seems to cease working when brass is still present, run some carbon removing cleaner through. Bore Tech C4 and Slip 2000 Carbon Killer are both good for this, but Windex isn't bad if you use a brush. Just avoid a petroleum-based product so you don't leave a layer of oil for the Cu++ to fight through.
 
Thanks guys.

I tried wipe-out for a couple of hours and also CU (after wiping the bore down) along with couple of passes of J&B. The bore is mostly sparkling clean now except for a couple of thick "skid marks" of brass about 2" aft of the muzzle where I think it could possibly affect a passing bullet prior to muzzle exit. These are the ones that have been resistant (including to CU++ which I have and tried) but I haven't tried soaking for a long time with CU++. I have KG12 and was big fan of it until I discovered it can possibly cause an oxidizing reaction of some sort if it seeps down into the recesses of the receiver.
 
Stop Press!

I Have a couple of bottles Shooter's Choice MC 7 which I've never used before, so I thought I'd give it a try. In just one application, BOOM! brass and remaining residual other stuff gone. Now that it's gone I can now see why I had such a hard time with it. It resembled a thick stubborn patch when viewed with my hawkeye--instead what it really was were areas of pitting in the bore that had entrained brass into it. Pretty much nothing I can do about that short of some kind of lapping, but I'll have to fire it first to see if it makes all that much difference, it's a big bore hunting rifle used exclusively at close range so I doubt the user (not me) will care if it's only 2 MOA.
 
Ha! Glad you found a solution. I'm puzzled that the Cu++ didn't do better.

If you read the reviews on Midway, one shooter claimed MC-7 pitted his stainless bores. I'm not sure I believe that, but I mention it because it could be the person blaming KG-12 for corrosion got the cause of the problem wrong, too. Experiments are in order.
 
Ha! Glad you found a solution. I'm puzzled that the Cu++ didn't do better.

If you read the reviews on Midway, one shooter claimed MC-7 pitted his stainless bores. I'm not sure I believe that, but I mention it because it could be the person blaming KG-12 for corrosion got the cause of the problem wrong, too. Experiments are in order.
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KG12 definitely leaves a crystal of some sort behind when it combines with raw metal from what I've observed (if not thoroughly removed). The hard part is figuring out if it's in reaction to the presence of some other kind of lubricant or solvent. Same can be said for many solvents. I too use bore tech for my day to day cleaning needs.

I've had several brand new rifles/barrels arrive over the past couple of years with similar "pit patches" near the muzzle from different manufacturers. I can't rule out that in the case of the rifle I'm working on that it happened while in the possession of my friend, especially since he's hunted with it severe weather environments and has never cleaned it; but it's entirely possible it arrived from the manufacturer that way IMO. It could be reaction to chemicals/gunk left in the bore--my pet theory is that in the production line when the rifling button is pushed/pulled through the barrel debris accumulate and get caught in front and get "plowed over". It may be pure coincidence, but I've seen these pit patches usually within 3 inches or so of the crown/muzzle. I could be off my rocker, too.
 
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I've seen the crystal, but just assumed it was crystalized reaction product from eating the copper. Of course, such a crystal could cause corrosion if it is hygroscopic and the corrosion inhibitors are used up or gone.

Is the MC-7 ammoniated? I've never tried that particular one.

What sort of condition is the bore in overall? I'm wondering if some light firelapping would help. Or Tubb's Final Finish process. It should take the sharp edges off the pits. You can, of course, treat the bare bore with something like Sprinco Plate+ Silver before he shoots it again. That should also help keep stuff from accumulating so easily in the pitting. Also, if you are loading the bullets, you can treat them with hBN or add Tubb Dust to the powder.
 
I've seen the crystal, but just assumed it was crystalized reaction product from eating the copper. Of course, such a crystal could cause corrosion if it is hygroscopic and the corrosion inhibitors are used up or gone.

Is the MC-7 ammoniated? I've never tried that particular one.

What sort of condition is the bore in overall? I'm wondering if some light firelapping would help. Or Tubb's Final Finish process. It should take the sharp edges off the pits. You can, of course, treat the bare bore with something like Sprinco Plate+ Silver before he shoots it again. That should also help keep stuff from accumulating so easily in the pitting. Also, if you are loading the bullets, you can treat them with hBN or add Tubb Dust to the powder.
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It could be the corrosive action (what I noticed seemed very slight) is due to being left behind and over time attracted water and reacted with it. I don't know, to me this stuff is like alchemy. What I saw was on the bottom of a round action where it had obviously trickled down the side from the breech.

The MC 7 is rather sparse on details when it comes to ingredients--it doesn't say it's ammoniated--but it sure smells like it to my nose, as does KG 12. BTW, I just got back from my first firing after cleaning, it seemed to shoot accurately (or as accurately as I could shoot 5 shots of .416 Weatherby magnum in a row kneeling off a front rest). The bore is horrendously fouled with copper! I'm surprised because the bore looked very well finished and smooth (once I got it clean before firing it) I suggested the fire lapping to my friend but I don't think he really cares about it that much (especially since I maintain and clean his rifles for him LOL).
 
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KG12 definitely leaves a crystal of some sort
behind when it combines with raw metal...
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I have to admit that I have never seen that in all my years of using KG-12.

But then I always dry patch out the chelated brown crud within 5 minutes -- rarely if ever
a second 5-min sequence -- and then leave the barrel BreakFree'd.




My favorite fun is watching a guy at the range unable to "get the blue out"
in 30-40 minutes of cleaning, and then my slopping a patch of K-12 into the
bore, dry-patching it out in 3-4 minutes... and then asking him to see
"if there's any blue left" on his next patch
 
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I have to admit that I have never seen that in all my years of using KG-12.
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What happened was is the KG 12 trickled down into the receiver's bedding as a result of my passing the soaked patch through, my carelessness perhaps. I agree that there is little risk from the KG 12 as long as you get it thoroughly removed after using, and what little affect it had when I missed it appears to be mostly cosmetic. I'd watch out for things like excess flowing out the muzzle and under the barrel and down the magwell if the patch is loaded. It did put a tough stain on a Mossberg barrel I have treated with marinetech.
 
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KG 12 trickled down into the receiver's bedding ...
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Gotcha. (Evaporates there.)
I'll have to run a simple "evap" test on a piece of bare steel and see what lies beneath when I scrape the dried residue off.

Film at Eleven.... ;):)
 
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