Proof barrel way out?

[spitfire_er]

I am chambering up a proof barrel. My first proof, but I've done about 100 barrels to date so, not my first time. Dialed in first 1.5" of barrel dead true off the bore with 513-504 mitutoyo. Through the headstock, 4 jaw with heavy copper wire and spider.

My question is I have the chamber end dialed in to start pre-boring. However my muzzle end is flopping around at 0.067" runout measured off the bore. Looking down the barrel when its running, it looks like a floppy piece of rope. I've never had a barrel this far out and wondering if its worth messing with or send it back and get a different one? I've had them up to 20 thou out and they still shoot great, but this seems excessive.

Pin in the muzzle end is just because I don't have in internal indicator that will read 50+ thou. Building this one for my upcoming elk hunt in 3 weeks so I'm on a time crunch.

I also set both ends dead true and the bore still looks like it flops around pretty bad.

After looking in my copy of "chambering rifles for accuracy" by Gordy and Fred, they reference random custom barrels up to 60 thou, but not often.

 

[jkohler]

Do you have a indicator that will reach up where the throat will end up? If so try and indicate that point and get the muzzle running true. If that looks better drill and bore your chamber to that.

 

[spitfire_er]

Yes, this is prior to a pre-bore on a 300 PRC, so I can reach about 1.5" in. Once I pre-bore I will indicate the throat, but not confident it will get better. Back end of the barrel runs fairly straight, then dives a few inches in from chamber end while my first 1.5" is running dead true.

I may give it a go. I had an x-caliber barrel once that was maybe 40 out and it shoots tiny groups.

 

[PigButtons]

Barrel mfgrs use sophisticated presses to straighten barrels. They may have skipped that step on your's by accident.

 

[WayneShaw]

How would you bend a barrel to fix a cork screw?

 

[boltfluter]

Personally, if you have the time and means I would send it back for a replacement. Most factory barrels are better than that. Occasionally a bad one gets through with all manufacturer's.

Paul

 

[spitfire_er]

Personally, if you have the time and means I would send it back for a replacement. Most factory barrels are better than that. Occasionally a bad one gets through with all manufacturer's.

Paul

That's what I'm leaning towards. I may take it out and set it up again to make sure I'm not missing anything somewhere, but I'm confident in my ability to set these up. I'm sure it would shoot, but for the price of the barrel, I expect a little better. If it was 20 TIR I wouldn't worry and just finish it. My only issue is by the time I can hopefully get another barrel if even in a week, that puts me less than 2 weeks out from my hunt. Basically no time to load for it and hoping It will shoot some factory ammo good or I land on a good load right out of the box.

I usually don't worry about a little wobble here and there, but this is the worst I've seen out of about 100 custom barrels installed. I've read alot of good things about proof and I get that one may slip through from any manufacture. I also understand that if I would have set this up between centers, I would have never seen this issue. The outside contour runs fairly true when centered up on each end.

Even though it may shoot great what are the odds vs a less curved bore. From everything I have read from top smiths writings, posts, and publications, they would send it back. I just hate to lose time here.

 

[butchlambert]

Barrel mfgrs use sophisticated presses to straighten barrels. They may have skipped that step on your's by accident.

I don't think anybody does that anymore. The ones I saw used the barrel like a hammer and beat it on a rail on the ground. Wayne is right, barrels do not have a bore in an arc.

 

[AlNyhus]

I'd have a dicussion with Proof before chambering it. That way, if it doesn't shoot there should be no problem with them replacing it. If it does shoot to your standards, everyone is on the same page.

For what it's worth, I had a Kostyshyn .30 1:17 that ran out close to .060 at the muzzle. We decided to index high side of the runout at 12:00 to get ahead of any horizontal tune issues and chambered it up. It was one of the most accurate barrels I've ever had. Won a lot of yardage and Grand Aggs with that 'noodle'.

Good shootin' -Al

 

[DaveTooley]

Barrel mfgrs use sophisticated presses to straighten barrels. They may have skipped that step on your's by accident.

None do that I use

 

[Northridge]

None do that I use

I have also witnessed this from time to time but if you can indicate the side your working on and the muzzle end the same when indicated it will shoot. "if it will enter the bore squarely and exit the bore squarely it will shoot" the biggest thing to not forget would be indexing the barrel in a manner that gets along with a barrel channel.. if your holding barrel overly tight as you attempt to index you may very well be bending barrel in a attempt to get it strait. good luck and also any barrel that I come across that had a less than favorable run out I set aside not because it will not shoot but to mitigate confusion with clients. I use them on my own competition re- barrels and surprisingly I'm a solid competitor using barrels with extra run out

Shawn Williams

 

[DocBII]

spitfire,

If I recall correctly, the instructions from Proof for the barrels is cut off that stepped portion where you are currently indicating. If correct, that may help the problem.

HTH,
DocBII

 

[spitfire_er]

Well, I went ahead and finished it today. Being that I'm leaving in 15 days for my hunt, figured as long as it shoots half ways decent, it will at least get me through my hunt. I have a backup rifle, but this was meant to be my lightweight packing rifle.

I will most likely call proof tomorrow and see what their take on it is. I know I may have shot myself in the foot by finishing it prior to talking to them, but I'm not going to hold them to anything after I cut it.

I figured the runout would get better once I got in the throat area. Wasn't the case actually went a few more out. Regardless, my chamber and throat look perfect. Flipped it and put a crown on it after cutting off the excess and dialing into zero. After I was all done I centered the barrel in the lathe for the hell of it. Running true on each end, the inside of the bore whipped around still. I also indexed the high side of the crown to 12 o'clock like I normally do.

The bedding is curing as I type. If I get time later tomorrow, I'll see if I can test it out. Even if its a 1 MOA barrel, I should be able to take an elk with it, but hoping it shoots much better than that.

 

[AlNyhus]

Looking forward to your results. What cartridge? -Al

 

[spitfire_er]

Looking forward to your results. What cartridge? -Al

300 PRC

 

[spitfire_er]

I called proof this AM. They are working with me to make sure I have a good barrel.

 

[HillbillyLongRifle]

I called proof this AM. They are working with me to make sure I have a good barrel.

What did they say about over .060 of muzzle flop?

 

[spitfire_er]

What did they say about over .060 of muzzle flop?

The guy I talked to said it is extremely rare that one would get through like that, has happened in the past though.

I don't know what their setup is, but I'm sure they are doing a very large volume with both lines of their barrels. I can understand a dud in a production environment, but its what they do about it that makes the company IMO. They are giving me a couple options which is above and beyond what I would expect from many companies. They are making sure I'll have what I want in time for my trip in a couple weeks. I'll post an update about what the final solution is when its all said and done, but so far, I'm impressed with their customer service.

 

[Rtheurer]

I cut down a 26" Barrel down 16" and found out how much curvature can really be in a Barrel... It was so far off center after we cut it down that We where fearful of a Baffle strike on my can. The barrel went 3000 rounds of Exceptional Accuracy in 26" form and is still shooting Great in 16" form.
Like the gentlemen above AlNyhu with the Barrel with a bunch of curvature. It didn't seem to hamper the Accuracy of the barrel one bit.
Do I want a nice straight barrel... Sure I do. Does it really matter? Probably less than i had thought.

 

[spitfire_er]

Well, with the consent of Proof, I went out and shot it with factory 212 eldx. First 3 at 100 were very promising and I was thinking we would be good. Then I took it out to 200 and it opened up a little more than I expected. I don't have access past 200 normally. If this were a factory rifle ide be extremely happy with these groups.

I understand that this is one load and not "tunned" per say. This is my first 300 PRC and everything I've read, guys are getting really decent groups with the ammo, so its a baseline. I may get roasted by some of you guys, but I think I will be replacing it. I just have a feeling that I won't be happy with it and ill always second guess it. It also nullifies the idea that I'm trying to build the best rifle possible, and if I'm second guessing it, its not what I would consider as close to perfect as possible. Don't really want to spin another barrel, but that's where I'm headed.