NEVER MIND -- I have a good Krieger 6mm Barrel

[Nomo4me]

I've got Krieger bbl that is just giving me fits. 8 twist, 6 x 47Lapua. Maybe 200 rounds downrange.

Bugger fouls horribly with copper even after 20 rounds. I really wanted to shoot the 88 grain bergers through it. First few rounds from a clean bbl shoot great then they start blowing up before they make it 100 yards.

Should I have a local smith slug this bbl ? What would he be looking for that might be of concern to Krieger? I've severed my relationship with the guy that barreled this thing for me so that's not an option.

MODERATOR: SKIP TO END -- Problem is NOT KRIEGER's Fault.

As a follow up:

Jon Beanland rechambered the barrel on this 6x47L and it now shoots beautifully and shows no more copper than any other rifle I own. It likes 108gr Bergers at 3150 fps via H-4350 and put 3 5 round groups into the high .3's Saturday while I was fireforming brass.

Problem was a rough throat all along.

Kudos to Jon Beanland of Oklahoma for being a superb smith in terms of quality, timeliness and communication.

 

[tome]

Re: How to determine if I have a bad Krieger 6mm bbl?

Krieger stands behind their products. As simple as a call & tell them your problems. The only rub, is the barrel has to come off & be sent back and then reinstalled when you get a corrected product back. I have a 1-8 tw 6br that shoots 80gr Bergers great..so it's not the twist.

 

[alf]

Re: How to determine if I have a bad Krieger 6mm bbl?

I'd step up to the 105-107 bullets, or even the 115's first.

You can't always make a barrel shoot what you want to.......

 

[TonyR]

Re: How to determine if I have a bad Krieger 6mm bbl?

Since you no longer do business with the smith, I wonder if your problems might be with a bad chambering job, particularly a rough throat that is getting fouled. What you are describing is what can happen when a barrel with a lot of rounds through it develops firecracking in the throat area. If you can get a borescope and have a look at where the fouling is building up, people here might be able to give you better advice.

 

[RonAKA]

Re: How to determine if I have a bad Krieger 6mm bbl?

I believe the 88 grain is the varmint bullet and will have the lighter jacket. Have you tried the 90 or 95 grain target bullets? They have a thicker jacket. Berger says bullets blow up because friction in the barrel melts the lead core. One thing to check would be the bore and land dimensions by slugging it. It may be too tight.

 

[Nomo4me]

Re: How to determine if I have a bad Krieger 6mm bbl?

I shot a couple of 1/2" CTC groups at 200 yards with this rifle and the Berger 108 gr so layed in 1000 of them for this season.

I shot 20 rounds a few weeks ago and cleaned the bore - pulled way too much copper out.

 

[Eddie Harren]

Re: How to determine if I have a bad Krieger 6mm bbl?

Have you contacted Krieger? I think it is only fair to give them a shot at standing behind their product, before outing them on an open forum.

 

[Nomo4me]

Re: How to determine if I have a bad Krieger 6mm bbl?

I'm not trying to bad mouth Krieger - their reputation is exceptional. But I recall hearing of a batch of 6mm bbls that were too tight. Just looking for input from others who may have dealt with that issue if that were indeed the case.

 

[TonyR]

Re: How to determine if I have a bad Krieger 6mm bbl?

Alf and Ron.
NoMo's original post talked about more than expected copper fouling from a barrel with relatively few rounds through it. I've never owned a 6X47 so I don't know what "normal" barrel life would be, but I think I'd be safe assuming it would likely be a lot more than 200 rounds regardless of the load.

I am trying to understand a similar problem in another caliber: a hypothetical gun that shoots great for the first 15 rounds in a string then falls apart in the last 5 rounds. I am talking F-Class standards of accuracy and 20 round string fire matches with unlimited sighters but more than 10 rarely taken. I know there could be a lot of reasons for this and fouling could be one of them.

Are you saying that switching bullet weights from the same manufacturer would stop or improve a copper fouling problem? I can understand how switching bullets could improve accuracy. It's the fouling part that I am curious about. I've not had this particular problem yet but it would be helpful to understand the variables involved.
Thanks.

 

[Nomo4me]

Re: How to determine if I have a bad Krieger 6mm bbl?

I think the suggestion to switch to heavier bullets was in reference to the 88's spinning apart.
This gun shot some .3" groups with the 88, and would have made a dynamite long range PD round, but they'd start to blow up after only 15 or so rounds down range.
I think the bore was fouling and tearing up the jackets. Guess I'll pull the barrel and send it off to Krieger and ask them to examine it.

 

[TonyR]

Re: How to determine if I have a bad Krieger 6mm bbl?

I think the suggestion to switch to heavier bullets was in reference to the 88's spinning apart.
This gun shot some .3" groups with the 88, and would have made a dynamite long range PD round, but they'd start to blow up after only 15 or so rounds down range.
I think the bore was fouling and tearing up the jackets. Guess I'll pull the barrel and send it off to Krieger and ask them to examine it.

Thin jacket Bergers blowing up in a hot, dirty, fast twist Kreiger is something I have experienced and switching to Sierras, Cauterucios, and thick jacket Bergers solved that problem, at least for me. I guess my question was more about possibility of a chamber with a rough throat because someone used a dull reamer or a too small pilot or any number of things that some people can do. I'm sure Berger will let you know whether they think it's the chamber or the barrel. Please let us know what you find out. It is an interesting problem I've heard a good bit about in the last couple of weeks and I would like to understand it better.

 

[RonAKA]

Re: How to determine if I have a bad Krieger 6mm bbl?

Alf and Ron...
Are you saying that switching bullet weights from the same manufacturer would stop or improve a copper fouling problem? I can understand how switching bullets could improve accuracy. It's the fouling part that I am curious about. I've not had this particular problem yet but it would be helpful to understand the variables involved.

I have no explaination for the copper fouling, other than it might be a tight barrel. I was really talking about the issue of bullets exploding, which will be more likely with a thinner jacket. But a tight barrel may link the two issues.

 

[Dans40X]

Re: How to determine if I have a bad Krieger 6mm bbl?

A bore scope doesn't lie!!

Rough as a cobb chamber/throat is my guess without a look inside.

 

[fdshuster]

Re: How to determine if I have a bad Krieger 6mm bbl?

Nomo4me: My first question is: where is the copper fouling located in the bore? Is it confined to the throat area alone? If the answer is "yes", then it would indicate a poorly cut chamber, leading to another question, Was a floating pilot reamer used? Is the copper at various locations further down the bore, a patch here and another patch there? And finally, the third type I've seen with my Hawkeye, as with my most recent new Krieger 1-8 6mm, a continuous coating from a few inches in front of the throat all the way to the muzzle. It looked as thought the bore had been painted, using a brush and a can of copper colored paint. The scattered patches and the one bore that had the complete coating all started to clean up after firing 10 to 20 rounds. They are now some of my most easiest to clean, and are extremely accurate. So: copper build-up in the throat = poorly cut chamber/throat. Copper further down the bore = a normal condition that just requires the normal shoot & clean break-in period. The only barrel I ever had that copper fouled for over (well over) 200 rds. was a utility grade, made by a big name maker, that had a bore surface that looked like a Nicholson file. It was returned for a full refund, but I've never had that experience with my Krieger's, Hart's & Shilen's. The newer Bartlein is impeccable/ one of the best. MY advice would be to clean the powder fouling out of the barrel, stop, and go into it with a borescope. As said before, "A borescope does not lie". Incidently, when I run across a barrel that copper fouls more than normal, I've never found any improvement by switching bullet brands, types, weights, etc. To me, a copper surface is a copper surface.

 

[SmokinJoe]

Re: How to determine if I have a bad Krieger 6mm bbl?

One other coppering pattern that I have observed on some of my barrels in the last few years is in the muzzle end for the last few inches. My take on that is the maker trying too hard to create a "choke" at the muzzle for better accuracy. If you combine a tight bore with a bit too much choke at the muzzle, I think it just starts to strip copper off the bullets, then compounds itself. Interestingly, this sometimes doesn't seem to hurt accuracy. However, it makes for very long cleaning sessions.

 

[flatlander]

Re: How to determine if I have a bad Krieger 6mm bbl?

Dittos, Joe. I have several 26"-30" tgt. bbls. from Bartlein, Krieger, & PacNor, in .224, 6mm, 6.5mm, 7mm, & .308; all of them copper in the last 3"-4" at the muzzle, and not a one of them copper foul (to the extent that's visible with a Hawkeye) anywhere else.

Like you, I've never noticed a drop-off in accuracy due to this fouling, but it does take awhile to get rid of it.

 

[alf]

Re: How to determine if I have a bad Krieger 6mm bbl?

IMHO, the choke is one needed part of the accuracy puzzle, think blunderbluss in the opposite extreme. I've noticed the copper in the muzzle end as well, but I believe it's more so of the jacket getting heated up in it's trip the length of the barrel rather than the choke being the culprit.

 

[fdshuster]

Re: How to determine if I have a bad Krieger 6mm bbl?

Yes to the above: I've also seen the copper buildup at very close to the muzzle only, and it also cleans up usually within those first 10 to 20 rounds.

 

[Nomo4me]

Re: How to determine if I have a bad Krieger 6mm bbl?

I had a local hack barrel this gun. First chamber job was rough as a cob and the fouling was unbelievable. He redid his work but brass now won't chamber after neck sizing in the new job. I'd imagine the throat of this rework might be bad as well. I fired 20 rounds and pulled lots of copper out after. I'm not going to have this bbl re-reworked but wanted to verify it was cut to spec inside before I fully accept the throat might be the cause of the extreme fouling.

 

[StraightPipes]

Re: How to determine if I have a bad Krieger 6mm bbl?

You can have a 6mm Kreiger 2 ways, .236 or .237 depending on your bullet selection. The .236 will cause the problem you describe. Your dealer will tell you that you can have it both ways if you ask. Is there a reason for this, this is what I would ask my barrel maker to explain.