Abrasive cleaners and copper fouling

[argh]

Last year I got a new rifle/barrel and was pleasantly surprised at how little copper fouling it experienced. My old Madco barrel used to give me a heap of blue patches with boretech eliminator, but would eventually clean up (was approaching 5,000 rounds), and was still shooting well. The new barrel hardly showed any blue/green on the patches after the initial black patches. I dont borescope, so was assuming the absence of colour meant no fouling ... ?
I have now put just over 500 rounds down the new barrel and gave it a good scrub with Iosso paste to get rid of any stubborn carbon build up, as has been my routine for a while.
Good news is that the accuracy came right back in tight. But, the barrel is now showing blue patches when being cleaned with solvent, noticeably more colour.
Has anyone else observed this? Did I change the microtexture of the barrel steel so it picks up more copper fouling?
It will be interesting to see over the coming months if it fouls more and how that will impact.

Thoughts
Adrian

[Barry Davies]

Any abrasive paste ( even the finest ) will put micro scratches on the barrel, which in turn pick up copper.
Solution--don't use abrasive paste --except in a case of " have to " ie a badly fouled barrel.

[argh]

Any abrasive paste ( even the finest ) will put micro scratches on the barrel, which in turn pick up copper.
Solution--don't use abrasive paste --except in a case of " have to " ie a badly fouled barrel.

I would have have thought that either button or cut rifeling would have put deeper scratches in the steel, and in any case, match barrels were lapped with an abrasive? Did I just put rougher or smoother scratches?

Not sure if the above is the case... just putting it out there.

[Barry Davies]

That's why you " run in " a barrel -- to get rid of those micro scratches that are put in by lapping. If you do the run in and follow up properly, you smooth off any ( micro ) scratches that are in the barrel --result -- no, or minimal copper pick up.
After " run in " and smoothing off by shooting, any use of abrasives will reintroduce scratches again -- minute as they may be they will pick up some copper. Probably will not affect accuracy but undesirable none the less.
As the throat erodes after many rounds it becomes rough and again picks up to some degree.

[Gyro]

http://forum.accurateshooter.com/thread ... e.3772530/
Check that out Adrian

[argh]

Thanks Gyro, some interesting comments on that thread, and pretty well what I have heard before.
I have always used abrasives very sparingly, and only every few hundred rounds to get rid of carbon buildup. What I did find interestingly was the change in the amount of copper being removed, and obviously being deposited in the barrel, and was wondering if anyone else had seen the same?

[williada]

Argh you may have polished her up too much with a good scrub out. Too smooth and copper sticks like plasticene to glass.

[!Peter!]

Argh you may have polished her up too much with a good scrub out. Too smooth and copper sticks like plasticene to glass.

Out of interest williada, if the bore has been smoothed too much can it be recovered with a few strokes of a lead lap and a course paste (i.e. say 300 grid)?

[bruce moulds]

talking to a benchrest shooter recently revealed that some in that discipline now consider it necessary to re run in the barrel after using the likes of j.b. paste.
this came as a surprise.
bruce.

[argh]

Just to clarify, maybe I should call it copper trace rather than fouling, and is not at all bad, just noticeably more than prior to pasting. (And less than my last barrel)
I only ran two Iosso patches down the barrel (6 or so passes each patch) so dont really think I overdid it, and am as always aware of not over cleaning with any abrasive.
The accuracy increase after however was noticeable and groups shrunk back to what I was used to from this barrel, and will keep going with this cleaning method every 500 rounds of so. It will be interesting to see if the copper trace does slow down after a new "break in"

[williada]

Hi Peter, yes it can but my advice is to use aluminium oxide because it breaks down into a slurry. For other contemplating the effort, don't use silicon carbide or diamond paste. Do use it on a cast lead lap and not on a patch. My preferred method is before a chamber nip and before a minor re-crown on an older barrel to eliminate over scrubbing with the lap as it creates a bell in the bore on return strokes. Otherwise on a touch up, strokes are fewer rather than numerous. Integral to the lapping is the use of a lead slug to feel for erosion etc which can be confused with tight spots and to check with a bore scope. Lead will shrink on casting and before it is bumped up to size it and the bore should be well lubricated. Don't put too much cutting compound on the lap. Heavier grits are primarily used before the barrel blank is chambered to remove tight spots which are easily felt. It was common to see tiny feathers on buttoned barrels following buttoning. The lap only touched the bore up rather than lapped it to a dimension. Longitudinal scratches from cut rifling are not so much a problem. Firing further shots soon laps the barrel and cleaning it thoroughly is important as the bore surface work hardens.

[GSells]

Only way to check what you are doing is with a borescope . If accuracy went up you must be doing something right . Keep doing it ! The target tells the picture.

[!Peter!]

Many thanks for the detailed response williada!!

[Frank Green]

I'm o.k. with JB bore compound but not the bore brite.

Same goes with other paste cleaners or even a cleaner like Witch's Brew.

What ends up happening is you are polishing the bore smoother and smoother when you use the abrasive. The copper wants to stick then. Usually when a problem like this starts with copper fouling you cannot make it stop.

Also the aggressiveness of the paste cleaners and using a brush as well you can damage the bore of the barrel not to mention changes sizes.

I wouldn't use a paste cleaner until the barrel is getting on it's last legs and or if it's a factory barrel that is fouling badly to begin with. Then you've got nothing to lose.

Later, Frank
Bartlein Barrels

[Frank Green]

Look at the attached picture. This was from a previous thread a couple years back. I also have part of the barrel here as well. The gouges are from the brush trying to rotate with the rifling. The lands stick up so they take the brunt of the beating.

Even using witch's brew. The argument to me was it's not a paste but in a liquid form and hence forth not as aggressive. This is true but it's still an abrasive. I had one customer in one year wreck 3 different barrels. All of the damage started to show in about a 100 rounds. His last 6.5mm barrel in a hundred rounds of being fired and being cleaned the gouges where showing up and he actually polished a .001" out of the barrel.

The attached picture .002" was polished off the lands and .0015" was polished out of the grooves.

Later, Frank