Copper fouling on threads of barrel

[CBRpilot]

I've got a stainless barreled 300 WSM from Browning. I had it threaded, put a brake on it, waited a week, took it to the range and then put 15 rounds through it. Never took the brake off for inspection. Waited a week after storing it in its case (inside the home), removed the brake, and this is what I see:

Green buildup would be copper, so can I just use a mild copper solvent to clean up the threads and not have to worry about corrosion or thread degradation? What can I use to help seal the raw stainless so I can help slow this buildup in the future? I know that carbon build up, when left alone, will attract moisture and lead to rusting. Will copper do the same? I just want to make sure I don't need to go back to my gunsmith to have this addressed. He has a great reputation and when I asked him what he thought (after sending a few pics), he said it looks like carbon buildup and to just clean it and see what happens after the next range trip.

Last pic is just a shot of the end of the rifling on the tube...does this look normal? After the initial break in of 30 rounds and a cleaning, I've put 40ish more rounds through it without a cleaning. Looks like copper build up to me.

 

[LV 426]

Could be some kind of antiseze on threads??????? Glock uses some.
Clean barrel one more time.....?

 

[CBRpilot]

Could be some kind of antiseze on threads??????? Glock uses some.
Clean barrel one more time.....?

Spoke with the gunsmith, he didn't apply anything to the threads after cutting them. Anyone else?

 

[leadbullet]

That is the outside of the barrel, it won't hurt anything that matters like accuracy. Your barrel will be burned out and replaced before any kind of erosion affect anything.
Cheers.

 

[JBRC]

The copper is atomized upon firing and is re- deposited upon the gases cooling. Completely normal. But, the gases usually don't travel very far up the threads though.

 

[buffybuster]

Much ado about nothing. Totally normal. Copper vaporizes in the plasma and deposits here and there. If it really bothers you clean it; otherwise keep shooting it until the accuracy falls off. Then clean and repeat.

 

[ZombieMonkey]

Buffybuster's post sums up my thoughts on the matter quite well. Don't worry about it until the barrel tells you it needs to be cleaned.

If you think that is bad, take a look at a QD suppressor mount on a well used 10.5" AR-15.

 

[MitchAlsup]

The copper is atomized

The choice of words is "ionized" or "vaproized" but you probably mean vaporized.

 

[meatwaggon]

The choice of words is "ionized" or "vaproized" but you probably mean vaporized.

If you are referring to a direct phase transition from solid to gas the correct term is actually "sublimated". I think it would take a textbook stating directly that this is what happens, or else a professional chemist who works in the industry to know whether copper alloy going down a barrel sublimates directly from solid to gas, passes through a liquid phase before becoming gas ("vaporizes"), melts into a liquid phase without subsequently becoming gas, mechanically "atomizes" into fine particles instead of becoming technically a "gas", or a combination of some or all of these processes. Any of these could result in copper deposition on/in barrels.

 

[CBRpilot]

Great responses. I discussed this with a friend for a bit and he had the same answer, although he didn't think the copper would have made it's way down that far on the barrel threading. I'll just brass brush it off every couple of months to keep it from making brake removal difficult and keep on shooting. Thanks guys