Bad Barrel?


Well-Known Member
Apr 24, 2014
Central Idaho
Need help deciding what to do next, having issues with a barrel. Cartridge is a 7/300 Win, H1000, 180 Berger Hybrid and VLD's @ 2900 to 3140 with an 8 twist. Top 3 barrel manufacturer I would say, cut rifled.

First shot down the barrel had quite a lot of copper fouling, much more than any of my other custom barrels. Shot 1/clean for the first 10 rounds. Copper didn't seem to get much better or worse. Started shooting strings of 3 then clean, didn't really do any better or worse. Chamber goes from no pressure to pretty heavy bolt lift in about .4 grains and it's not consistent. Initially it pressured out at 3140, some days it can be as low as 3090, same elevation and temp.

Called the manufacturer and told them the deal, they said to pull all the copper out and run some JB through it and see what it does. Took me about 2 days of morning, lunch and evening to get all the copper out with BT C3. Took about 15 strokes with JB in each 3rd of the barrel (what the rep I talked to suggested.

Took a mild load (for cartridge) of H1000 and 180 VLD's and shot 1, 3006 fps. After 1 shot the bore was fouled terribly for the last 2/3rds. That's where I am at. Not sure where to go next. They said I could send it back, but it would take quite awhile to get it looked at and get a new one to me. Season is here and I'd like to get it going.

First pic is after pulling all the copper out and running JB through it. 1 shot. Total of 87 down the barrel.


Second is of a crack or imperfection in the throat, just where the rifling begins. Fairly sure this has at lease something to do with where the copper is coming from.

Third is of some strange diagonal marks that start about 6 inches ahead of the throat and continue on each rifling down the bore. They do not really seem to be spaced incrementally, but more or less there are 2 of them about .2 inches apart and then show again about 3 inches down each rifling again. I have no idea what they are from, I can't imagine I did then when cleaning it. Used nothing but Boretech and JB with a bore guide, carbon rod, nylon brush and proper jag. Some are deeper than others, this is probably average.


I would love to just shoot it and see what it does, but it is so inconsistent with pressure that I'm a little hesitant to.

Any Ideas?
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The diagonals are left over tooling marks, they should not be there. I think the barrel has a bad lap job. The weird mark at the beginning of the lands should not be there either. I don't think you will ever break it in so that it stops coppering like that. That is just wrong from a top tier cut rifle barrel maker. IMO anyways.
Wow... seems like your doing all the right stuff. Maybe just try a different load/bullet that's lighter, just for kicks, and see what happens. Also, try to check to see if you twist is what it's supposed to be. Also, give it a big jump to see that helps. It's like the bullet is going through an extreme amount of stress trying to go through the tube.

If your hunting, I'd go straight to your backup rifle. It's probably a 30-06, which is maybe what you should'a picked anyway (ha, ha). Real reliable. I wouldn't think twice about sending my rifle back to the manufacturer.

I sent a rifle to a gunsmith that was very well known here to chamber in 338 Norma. Not only did he send it back to the wrong person, but, once I finally got it back from the stranger who ended up with it, it hit pressure so far below it's anticipated standards, that it was totally unusable. Gunsmith was no help and wouldn't reply to my inquiries. He later had some legal crap that goes on with gunsmiths that rob Peter to pay Paul. Anyway... I wouldn't over stress. Write this gun off as a good idea gone bad. Put a fairly decent rifle in your hands that doesn't completely stank. Here's a funny... when your old and useless... chances are, you'll probably be using this same rifle for all your big game hunts.

Send your hot rod back to be checked and hunt like a real hunter with your back up. Don't be sad. Lean that "your the weapon" and not the gun. Oh, sure... a good gun is pretty OK but you know...
I didn't see you mention how it groups? Is there a point in sequence it groups better than others? Clean vs fouled? How's it carbon fouling?

If I needed it in a short time frame I'd try the Hammer's first. If I thought the barrel manufacturer was going to be of help, I'd pull it as soon as possible and send it back.

If I was going to suck it up, and keep shooting it as is, I'd try fire lapping it.
I didn't see you mention how it groups? Is there a point in sequence it groups better than others? Clean vs fouled? How's it carbon fouling?

During pressure test and what little work up I did it would typically shoot 2 fairly close and then start walking. It had a hint of color in the carbon ring area, I scrubbed it out. It wasn’t anything though.

I just shot a few more through it, 72 grains of H1000, 180 VLDS in RWS brass. 3000 FPS and has ejector marks already. Fouling is obviously creating a ton of pressure.
them are some soft jacketed bullets, run some Sierra's thru it if you load up some more, get some Barnes CR-10 .then hit it with jb.
I've shot a lot of bergers and have never had the copper fouling he's getting.
In a quality custom barrel you shouldn't have to run J.B through it or anything like that to get it to quite coppering so bad.
After 87 rounds and this much copper it's time to send it back.
I'd be sending it back and finding a cheaper backup rifle for the season. Ruger American, Winchester XPR, Browning AB3 something along those lines to get you through the season if it truly will be that long for the barrel maker to get you a new tube. I'm very impressed with the XPR as a budget setup, and CDNN has a killer deal on them with a manufacturer's rebate. Hope it works out for you--very disappointing to have high expectations of a custom build and not deliver the precision you hoped for.
Those marks are nothing. Bore scope enough barrels, you will see that or worse from every maker. Those marks wont affect a thing, coppering or accuracy.
I think based on your comment about how long it took to get all the copper out, that you did not break in this barrel. When you do the shoot one and clean type break ins, you have to clean ALL the copper out every shot. If you dont, then you defeat the whole purpose. Its usually an 8 hour day of 5 shots, mostly soaking out copper. With that said, there is a lot of copper in that barrel for one shot. These higher velocity, larger bores will usually always leave a little copper but not that much. Still, it may end up being the best shooting barrel you have ever had once it settles down, if it does.
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