Copper in the bore

FrankenMauser

New member
Some of my rifles require some copper fouling to shoot their best.
Others prefer to be squeaky-clean.
Some don't care one way or the other, as long as the fouling isn't horrendous.

It just depends on the rifle (or barrel).
 

Northof50

Moderator
I have a T/C Contender barrel that accumulates copper. Sometimes I'll plug the barrel and soak it in amonia [generally, I believe that's the common component for dissolving copper] overnight. The next day, drain, then brush and run patches. If the patches come out blue/green - that's the copper.

I believe I read this in an article in Shooting Times years ago. To be honest, I never bothered with it after a couple of soakings.
 

JohnKSa

Administrator
It is not necessary to get all traces of the copper out of the bore, but some guns may copper-foul so badly that it is necessary to get most of it out to get decent accuracy. That's more the exception than the rule.
 
That's the problem I had with my DCM Garand. Over the National Match Course, a 50 round old standard competition, the last 20 rounds are 600 yards slow fire, so the part that demands the most of the rifle's precision is at the end, after you've accumulated some fouling. That rifle shot like a house on fire right up until nearly round 40, then the scores would start to drop, going from mostly 10's and X's down to picking up a couple or three 9's, and then in the last 10, 8's and even the odd 7 would show up. It would then take from after dinner all the way to bedtime working with Sweet's 7.62 (a strong ammonia-based cleaner) to get the blue patches to stop coming out for the next day's matches.

There were warnings back then not to use ammonia excessively in bores. That didn't hit home for me until I left a die with a stuck case the head broken off (thanks, stuck case remover) soaking in ammonia to etch the brass out. A few weeks later the case was gone and the ammonia solution was a beautiful cobalt blue but the die had a layer of rust brown all over it and was in need of repolishing. That convinced me it wasn't good to do.

Today there is no need to use ammonia. It's not even close to being as fast or effective as the chelating copper removers are anyway. I mostly use BoreTech Eliminator, but for a really tough bore I clean all the carbon out with BoreTech C4 and put in their Cu++ product or KG-12. Both attack copper hard and fast and keep on working a long time. Just give them 20 minutes and most copper will be gone. KG-12 actually keeps working longer and harder, but it doesn't turn green or blue, so you need a borescope or Eliminator or Cu++ to determine when the copper is gone from using it.

I've restored a couple of Mausers to shooting condition that had little visible rifling left by starting with Slip 2000 Carbon Killer. It's the fastest carbon remover, but it isn't odor-free like the Bore Tech stuff. Letting it sit 15 minutes loosens most of the carbon caked up between the lands for brushing out. A couple or three applications and the rifling magically appears. The copper remover goes in and voila!
 

Northof50

Moderator
Never had an issue with ammonia. But, then again, I would never leave it in a bore [or anything else] for a few weeks.
 

OzeanJaeger

New member
My experience:
When I've done a lengthy break in procedure those barrels don't foul nearly as much.
The one's I've bought used (possibly no break in) seem to foul a lot.

I don't leave ammonia in very long either, and then I hit it with Kroil after the patches come out clean and dry.
 

Yosemite Steve

New member
My question now is: How should I move forward with this freshly cleaned 30 year old barrel. There is some pitting, but it has been taken back to bare steel. How many shots before cleaning? I could really use some advice here!
 
The ammonia hazard is concentration dependent and can also be mitigated by corrosion inhibitors. The maker of Butches Boreshine told me that as part of their development he put a clean piece of 4140 steel in it for six months with no effect visible under a microscope. It seems to be there is some critical concentration level or set of conditions that determine whether it becomes a problem or not. I have never seen a chemist explain what they might be, so there is some element of a crapshoot involved. I will say I've never heard of a problem with it on stainless, not even when used as the electrolyte in an electrolytic bore cleaner, something The Fouling Shot reported years ago causing rust to rival any corrosive priming might do on soft muzzle loader steel. The issues have all been with plain gun gun steels.

But the ammonia still doesn't hold a candle to the newer (relatively speaking) chelating cleaners.

http://www.slip2000.com/blog/precision-shooting-magazine/
 

Yosemite Steve

New member
The gunsmith told me today that I should clean it every 20 shots if I want to keep the copper out. It has pitting and will foul easily. So I need a method that will clean it quickly at the range... or shoot it dirty? He said it isn't ruined but it will foul rapidly.
 

Yosemite Steve

New member
You could try firelapping it.
Do you have a favorite instructional?

This morning I ran a very tight wad of paper towel down the bore to get every remnant of oil I could muster and out the end came an imprint of the rifling that I have not seen before. Inside each rifling are about five tiny uniform grooves that follow the rifling. I have never seen any images of rifling that show this. Seems like more places for fouling to linger.
 

Dufus

New member
Do you have a favorite instructional?

I use NECO for fire lapping and I am certain that Unclenick does as well.

My favorite fire lapping load uses the right sized cast bullets over a charge of Red Dot powder.

I recently had to fire lap a Savage barrel (308 Win) and used 5.0 grains of Red Dot. Works like a champ.
 

tobnpr

New member
Forget about firelapping on a pitted bore.
I don't believe in using them at all, but to each their own. Any bullet swaged down the bore is going to- by sheer friction- erode minor machining imperfections over time. Abrasive boolits enlarge it all, essentially causing premature wear.

In any case, for this application it would be useless. You've got a trashed (pitted) bore. Can't fix it, it's done. Clear out the copper, shoot till accuracy suffers, strip it out again.
Lather, rinse, repeat.

Barrels are like tires- they wear out and need to be replaced.If it's not shooting accurately enough for your needs, re-barrel it, hang it on the wall, or sell it as a project gun. You never mentioned what it is...
 
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