copper fouling

[williek]

I have recently purchased a used 6mm Remington bolt action that shoots sub minute of angle for about seven or eight shots then copper fouling causes the accuracy to fall off.
I need some good suggestions on how to smooth the bore without harming the accuracy. Any ideas?
williek

[Lawdog]

Have a gunsmith "lap" the bore for you.  Lawdog
 

[beemanbeme]

It is very hard to lap a barrel once it has been installed without belling it at one end or the other or both.  
Clean the rifle when accuracy falls off and follow your cleaning with some JB paste per their instructions.  It may take a bit of time but you will smooth the barrel out.  
If you are indeed getting sub moa groups, I certainly wouldn't do anything that was too radical to smooth the bore.

[Buckskin]

Ah back to the age old question of breaking in a barrel.  This is one reason why you should.  Cleaning the barrel and using a copper remover between each shot for the fist 5 or so, then gradually decreasing your cleanings.   This would have prevented that big build up, and made copper fouling removal a lot easier.  I have broke in several barrels this way and on all of them, copper fouling is reduced after every shot and eventually is esentially eliminated.  You will need to use a good quality copper remover gradually disolving that build up.  It may take a while, just keep cleaning until green is gone.

[DannoBoone]

I have recently purchased a used 6mm Remington bolt action that shoots sub minute of angle for about seven or eight shots then copper fouling causes the accuracy to fall off.
I need some good suggestions on how to smooth the bore without harming the accuracy. Any ideas?
williek

You mentioned firing 7 or 8 shots, then accuracy going south. How rapidly
are these shots being fired? The bore diameter will expand too much for
accuracy if it gets too hot. I allow a few minutes between each shot for
cooling.

Try beemanbeme's suggestion with the JB Bore paste. If that doesn't do
the trick, you may have to resort to fire or hand lapping. I have a .25-06
Encore barrel which came with such a rough bore that you could see fibers
left after running a patch through it (the chamber was also reamed too
deep, but THAT's another story).  I decided to hand-lap using Flitz Metal
Polish. It took 100 passes (from breech to muzzle direction only -- and
you need a bore guide), but that took care of the bore problem. You also
need to make sure the Flitz or whatever you use is totally cleaned out
of the barrel prior to firing.

[williek]

The barrel isn't new.  I bought it from a friend and I knew it was an accurate weapon when I purchased it.  I do not know how carefully he cleaned the barrel. It is still accurate, shooting under an inch until a few shots have gone down range then it begins to slowly open the group.
I shoot very carefully and slowly. Fire one shot, consult the spotting scope. reload, watch the wind flags so I can shoot in the same condition as much as possible, and I do not shoot until the conditions are right.  I would expect that at least two to three minutes between shots.  I got past the fun of bang bang shooting many years ago, although hunting snowshoe rabbits with a .22 auto in the winter is still a lot of fun.
It will work just fine for a hunting rifle; however, I had hoped to use it on prairie dog shooting which will not work out if the accuracy goes south after a few rounds.
A number of people have suggested JB paste even though it might take some time.  I think I will try using it each time after I have cleaned the barrel and see if there is any improvement.
Thank you for all your suggestions.
Good Hunting,
williek

[nomosendero]

williek
Unfortunately, many if not most factory barrels have rough bores. Of
course there are some exceptions. I have worked with several Rem. Model
700's that were very accurate but fouled badly.
 In most cases I have been able to break-in the barrels as Buckskin suggested with good results. But a couple of the Sendero's that I worked
with would have none of that! On one of these I followed a very detailed
break-in procedure I read about from a famous Bench Rest champion
named Jim Shultz. I removed the barreled action & poured boiling hot,
soapy water down the bore, scrubbed & followed with boiling hot rinse water. This was done to remove all shavings & solvents. Then I scrubbed
a great deal with JB Paste with a patch wrapped around a smaller cal.
brush. I did this several times with new patches & then cleaned the bore.
Then I started the break-in by shooting 1 round, cleaning doing this 20
shots, then 3 shots 5 times then 10 shots 3 times. Each time I used Powder Solvent & then Sweet's, "this was a few years ago before some of
the new stuff." AFTER I DID THIS THE GUN STILL FOULED BADLY!!!!
  I took it to Wyoming that fall & took a Mule Deer & Antelope & a Whitetail
back here in Ar. The next summer I found out about DAVID TUBB'S FINAL
FINISH!!!!! I had studied other fire lapping kits & was not impressed with
those. Here is what Final Finish did for this rifle & others since then.
1. Reduced fouling & cleaning effort big time. I went from using a sack full
   of patches to just a few each cleaning!
2. Increase in accuracy. This gun went from a .80" Rifle to a .50" Rifle!
3. No longer necessary to have a fouling shot since almost no fouling
    occured after the first shot at that point.  
4. Increase in velocity. The pressures were a little lower in my existing
    loads now which made them a little slower but I was able to increase
    powder charges at the same pressures & increase velocities 50-75 FPS.
  I have no stock in this company & no I don't sell it. I wanted to share this
  info because it has saved me alot of heartache since then.
I know one place that sells it is Lock Stock & Barrel.

SO HERE IS THE SOLUTION!!!!!
Do a basic break-in more like Buckskin mentioned "possibly not necessary since yours has been fired some but it won"t hurt." Then do the Final Finish per the instructions. If you don't reload, get someone to load these for you. Then clean your gun & enjoy!  

[cal sibley]

You might consider a product called Tubbs Final Finish.  I think Sinclair carries it.  It'll smooth out the bore and eliminate the rough spots to which copper fouling becomes attached.  You can also do the job with JB Bore Compound, but be prepared for a long, arduous task.  You'll never get your barrel to stop its copper fouling until you get the rough spots out.
Just one mans opinion.  Best wishes.

Cal - Montreal

[nomosendero]

cal sibley

This is the product that I discussed in the post right before yours!

[DannoBoone]

Have heard good things about David Tubb's Final Finish. It was the fire
lapping system I was about to choose if the Flitz hand-lapping procedure
had not worked. Please note that hand-lapping will not wear the rifling as
most fire lapping will. Should you not get desired results from hand-lapping,
however, the Final Finish system can pick up right where ya left off with
hand-lapping, resulting in much less barrel wear than other fire-lapping
systems.

With hand-lapping, one needs a good chamber/bore guide. With the Final
Finish system, you may need to get a different type of powder, and you
MUST have reloading equipment (or at least access to the equipment). More
info can be found at:

http://www.zediker.com/tubb/finalfinish.html  ..............................and I
have no affiliation with them, either........just hope this helps.

[cal sibley]

You can get rid of the copper without hand lapping the barrel, but you'll be one tired puppy by the time you finish.  Unfortunately, copper fouls in layers.  Sometimes you think you've got it all when there's lots more buried beneath other fouling.  I think that's where JB Bore Compound comes into play.  It's an abrasive and removes some of the other gunk enabling you to get at the copper you couldn't previously reach.  Copper will attach to any irregularity in the barrel, pitting, rough spots, you name it.  Shooters that use the stainless steel, polished (lapped) barrels offered by the better barrelsmiths have far less problems with copper fouling.  Best wishes.

Cal - Montreal