Home Forums Hunting & Shooting Gunsmithing Big bore copper build up problem & firelaping

I have a CZ 416 Rigby that gets copper build up worse than any rifle I have used. In my varmint rifles and med bores ('06, 270 ect) I have to use Sweets every 40-100 rounds to keep the copper out. I determine this by when my Shooter's Choice patches come out green at the end of cleaning.

Perhaps in hunting rifles I shouldn't even worry about it and I'm just being an overly meticulous rifle looney.

After 5 rounds of Partitions or Barnes Solids in the Rigby I can easily see copper on the lands with the naked eye. After regular cleaning it then takes 3-4 applications of Sweets to get it out.

I just tried the Wheeler Engineering firelap process with cast bullets at low velocity. I then fired 5 Partitions. No improvement.

Is copper buildup like this normal in big bores or with these bullets? Should I even worry about it?

I am hesitant to firelap again as the rifle is accurate and I don't want to damage it.

Any thoughts?

I would stay away for firelapping. All is does is wear out the barrel faster. Look into KG INC. They make a copper remover called KG12 that will remove copper w/o harming the bore.

I had a Ruger 22 pistol that was that way. Cleaned all the fouling, copper, and oil out of the bore and used EEZOX. It took three times after shooting but no longer fouls to any degree. Stuff worked on my M1A also. Fellow HI Power shooter got me to try it.

You can brush lap it, but if the rifle is accurate I'd put up with the fouling. FWIW, I did that on a .260 that my Dad talked me out of and it shoots great. Mtn rifle contour barrel, SS and much easier to clean, not as much fouling.

MD wrote an article about it, just can remember in what magazine. Either Rifleshooter or Rifle.

Outers Lead / Copper out electolises.

Spot

Allot of times it isn�t the �bore�, per se, that is causing excessive copper fouling...it is roughness in the throat area where the tool marks from chambering run across the path of the bullet rather than with it. John Krieger explains this very well in his instructions for breaking in and cleaning rifle barrels, which can be found on his web site.

In essence,copper that is shaved off when the bullet moves through this area is vaporized by the hot gas at ignition and is then deposited down the bore as the gases cool. Since copper sticks to copper very well, if the copper in the throat area isn�t removed completely it will build up there and some of it will continue to be �blown� down the bore and deposited every time you fire a round.

If you use a copper dissolving product when cleaning make sure that the patches come out clean without any traces of green on them. You might want to consider using an overnight product like Wipe-Out to make sure you get all the copper out of the throat and see if the problem persists.

completely de-coppering is a pain because the gun will usually be erratic for 10 shots of so as you re-foul it. I'd rec shooting with just regular cleaning for a while to see how long accuracy lasts. you may well get 50-70 or more rounds before you really NEED to de-copper.
I've had a few that did so and tended to smooth out over time (I like JB for this).