Cooper and carbon fouling.

[Shortmagman]

A few years ago i had Bartlien replace the barrel on my Winchester Model 70 270WSM. I was quite pleased with the way the gun shot with the new barrel. However this barrel copper fouled more than any gun i have ever owned and than is more that 20. I called Bartlien and told them about the fouling. I was told to shoot 5 five shot groups and see if the accuracy deteriorated. I shot the groups and the accuracy held up. I thought as i shot more and cleaned the barrel would smooth out. That has not happened! This barrel both carbon and copper fouls like you whould not believe.

I just bought a cheap bore scope and took some pictures and there is no wonder why. It looks like alligator skin.
My question is what should i do?

The gun still shoots well. With a number of loads it will shoot. 1/2 in three shot groups and only a few hundred rounds have been shot. Not sure exact total but maybe 300.
Should i just keep shooting until the accuracy disappears?

 

[Shortmagman]

Picture of the barrel

 

[BallisticsGuy]

Yup and don't clean it just for the sake of cleaning it. Clean it when accuracy degrades, then shoot a few to foul back in and enjoy the rest of your day. Gator skin in the throat of a highly overbore gun that's been shot a bit is normal. I suspect you've shot it hot a bit and probably more than 300rounds. Throat life won't be super far past 1000rds anyway. Magnums eat throats. Shooting them hot makes it worse.

 

[JuddL]

^^^ he's right ya know

 

[Shortmagman]

Thanks guys. I have tried not to shoot it hot. I try to stay from five shot groups. It is a hunting after all.

 

[ShtrRdy]

I had a Krieger barrel that seemed to copper foil easily. And I even went through a break in process. Eventually at 350 to 400 rounds it settled down and doesn't copper foul much.

 

[Shortmagman]

I am still hoping that mine will break in. it has fouled from the first shots. I thought a premium barrel would be a lot smoother.

 

[ShtrRdy]

That's what I thought too. I've had a few other premium barrels and did not have this problem. The barrel of mine that fouled easily was really hard to find a load it liked.

 

[Shortmagman]

Mine has shot some great groups. It does not like all loads but it will shoot a three shot group under 1/2 in. Here is one example.

 

[ShtrRdy]

That's awesome!

 

[Varmintnv]

Wh your pic shows is fire cracking. It has nothing to do with a "cheap or premium barrel". It has to do with igniting a huge flame inside a small hole. Hence the comment above about overbore magnums. If you wanna run with the big velocity dogs, ya gotta be willing to get off the porch.
Any cartridge capable of 3100+fps is going to foul a bore, period. I only have 1 gun that doesn't make it to 3000+ fps territory, and even that little 7mm-08 fouls the barrel. It'll go longer between cleanings than my .22-250AI or my 28 Nosler, but still needs to be cleaned every 30 rnds or so.
My 28 Nosler shows almost as much fire cracking as yours and it has less than 100 rnds down the pipe! It's a PacNor SS Super Match grade barrel to boot.
The old addage " you gotta pay to play" certainly applies to shooting magnum rifle cartriges.

 

[Shortmagman]

I guess that my question and the picture has caused some confusion. I have a number of mag rifles ( 7mm Rem mag, 7mm SAUM, 270WSM etc]. I do understand what overbore does to a barrel. My question was related to why this barrel copper fouled from the very first shots. My 7mm's don't, after years of use.In fact the factory Winchester 270 WSM barrel that came on this gun did not. This barrel is the king of copper fouling in my collection.

 

[tobnpr]

Comments above echo my initial reaction.
IF that's just ahead of the leade, appears to be typical erosion- and wouldn't be a factor for copper buildup.

Clarify where the borescope was when the pic was taken? If it was just ahead of the chamber take some additional shots further down the barrel. I've never seen anything like that (in cut, button, or hammer forged) other than as firecracking.

 

[Shortmagman]

Thanks for the response. The picture was just ahead of the chamber. Here is a couple of pictures further down the barrel