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Questions about barrel/throat appearance

tmccoy

Plastic
Joined
Jul 28, 2009
Location
Jacksonville, FL
I'm interested in hearing thoughts about what I'm seeing when I borescope one of my competition rifles (Highpower across the course). It is an Obermeyer 5R in 6.5 Creedmoor. When I had it built, I didn't really have a smith, so I had the action maker fit and chamber the barrel. (Won't mention names, but rhymes with Fierce, and starts with a P). But I got worried when one of the guys called me to talk about the tight bore. I know Obermeyer barrels have tight bores, but they acted like they had never heard of Obermeyer or a tight bore and how it was soooo tight and they didn't know what to do with it. Anyway, so I get the gun back and have never been pleased with the accuracy, struggling to get any loads to keep under 1" at 200yds, more like 1-1.25" is average regardless of what I put through it.

Here are some photos of the throat area. I haven't scoped a lot of "custom" barrels, so don't know how much is normal in the way of tooling marks, but some is definitely not normal. Am I being too picky? Of course, if it shot better I wouldn't complain!

I appreciate everyone's help


This is a view of the throat with irregular tooling marks, and a fairly deep lengthwise mark
image.jpg

This is a sequence of three, from the throat area at upper left and going up into the barrel just past throat. The land is on the left, in the bottom of the groove are these clear gouges, and only in this one groove. This barrel has never had any sort of steel cleaning rod placed in it.
image.jpg
image.jpg
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The last one is what looks like a long groove in the bottom of this one land, starting about 5" in the barrel and stretching a good 8". The lands are on the far left and right side.
image.jpg
 
I know a few people that have bought bore scopes, then started looking into rifles that shot really well, and they saw all kinds of things with the bore scope that never showed up on a target. I think the bore scope for sure helped them do better work after they got it and had it there to use.

Bill
 
It certainly does not look like the best barrel in the world but to be honest you can't really tell much from a few pictures through a bore scope. You pretty well need hands on to get a good idea what you are seeing. It looks like a cut rifled barrel, in one photo it looks like the cutter may have had some material stick to the edge of the cutting hook (load up) and was dragged for a ways and left a bit of a scratch. In another picture it looks almost like you may have a step in a land. But even that's just a guess. I cant even say for sure that it's cut rifled going from those photos. With bore scopes you need to spend 10 minutes or so on a barrel going up and down, playing with the focus and you also need to get a good look with an iris and/or a high powered loup or camera lens to give some depth and perspective to what you are looking at. Learning to use inspection tools and knowing what to look for and how to interpret it can be as big of a pain in the ass as actually building the damned barrel. I started using a bore scope, loup and iris back in 1985 and only in the last 10 years have I started playing with digital photography and I have squinted down literally 1000s of barrels and I am still learning things.

Also, the bore scope will not tell you whether or not a barrel will shoot well. It only tells you if there is any deviation from the expected standard of manufacture. I have seen barrels that apeared perfect with inspection tools. I have run them slowly in a chuck in the machine while heating with a plumbers torch from room temperature to 150 to 200 F with a tenth indicator on the other end and had no change in run out. Yet when installed on an action they shot like hell. Others looked like hell inside and when warmed would warp and move around like a little kid doing the pee dance yet after installation shot like a million dollar bench gun. We have a good idea what generally makes barrels shoot better but we really still don't have a clue what makes them shoot good. Like the horse racers say "breed the best to the best and pray for the best."
 
Did anyone take an actual measurement to see how tight the bore actually is? rifling size ok? or was it just the pilot that was riding tight?

My 260 so far hangs around 1/2moa as well, had 2 or 3 .4-.5 5shot groups at 200 but overall not enough consistency to make me happy yet either mainly around an inch to 1.25 as you say, mirage is playing its parts, and this shooter here needs work too... Does have me wondering if its just the average we can expect as I'd like a consistent .5 at 200...
What's the best groups anyone has done with the 6.5 creedmoor so far? didn't think it was used much if at all in competition with all the 6.5x47.
 
You know, I have heard a lot of rumors of Obermyers being tight. My 308 bore runs .2999. That is not tight. Do you have tenth pin gauges to check it? What work and receivers that I have bought from John Pierce has been top notch. Now, have you visited with Boots about this or with John?
 
I put an Obermeyer 5R on a while back that had a little tool mark about 1/2" from the finished muzzle.

5R Tool Marks 007a.JPG

Went over it with Boots and he advised to not worry about it.

It shot extremely well so I quit worrying about it.

One of our local heroes re-barreled his Dasher with a Douglas air gauged and the inside of that barrel (through a bore scope) looks like a file that had been annealed and rolled flat. In other words, LOTS of radial tool marks.
That rifle is one of the most accurate guns on the west coast and has the wins and records to prove it. It definitely shoots better than the big name cut-rifled barrel that came off.

How does yours shoot??
 
Kendog, I would like to know how his shoots also. I haven't chambered mine. The one that I have is 11.25 twist. I had it recontoured to a #4 Shilen contour. It will become a 30 cal hunting rifle for big bullets.
 
Kendog, I would like to know how his shoots also. I haven't chambered mine. The one that I have is 11.25 twist. I had it recontoured to a #4 Shilen contour. It will become a 30 cal hunting rifle for big bullets.

I am sure it will shoot fine.

IF you don't use a bore scope, and keep tolerances to 50 millionths!! :D
 
Unless your a high master who regularly shoots in the upper 490s with 20 plus x I wouldn't worry about it. 1.5 at 200 is capable of a 10x clean. Just shoot the barrel out or If it really bothers you replace it and sell me that one for 50$ ill shoot the hell out of it. This is an xtc gun, not a bench rest gun. That kind of accuracy is acceptable for our sport , even prone shooting.
 
I really appreciate the comments.

Maybe I was just expecting too much, but I was underwhelmed by the work. I didn't bother to scope the barrel before shipping it off to get put on a new action, but maybe I will next time. I have always had good experiences with Obermeyer barrels in the past, so I didn't think about it. I guess I was more surprised by the gouges seen in the groove just past the throat. They told me the bore was at .254, which is what I've heard that Boots' 6.5s usually are. There were some other issues like the crown looking very rough, and the bolt lugs having about the same amount of contact as a stock 700 (had well under 1/2 lug contact).

I've already ordered another barrel, so I'm going to pull this one. Not really personally knowing a competent smith, I always just have to put blind faith in them that it will get the same attention as if we're his own gun, but I know that may be being naive as well. I just don't have anyone within driving distance of me that I know of. I know I don't need BR accuracy, but I have many years of Highpower experience and do routinely shoot in the 492+/788+ range, so I expect a gun to definitely be in the 3" or less range at 600yds.

I know there are lots of great smiths out there, but I'm definitely open to ideas about who I could trust to put his best effort into a gun. I have done a few simple barrel jobs for hunting guns, but don't trust myself quite yet for what I'm looking for here.
 
I've seen uglier bores shoot as well & never imagined what I saw in the 'scope would predict how well a barrel shot, admittedly with hunting vs comp rifles. btw: I'm confused when you say 'tight' and show the land dia vs the groove dia. My SMLE's 2-grooves' width isn't much, maybe 10% of circumference & jacket engagement, so I'm pretty much swaging to land dia. Wouldn't 'tight' be groove diameter in most 4-6 groove barrels (or 5R?) with 40-50% lands, and perhaps as important. Can you straighten me out on that? Slug it(?) or cast it to get groove dia? (Hope you don't mind the naive Qs guys, this is 'classroom' for me.:bowdown:)

I wouldn't say the OP's bore looks to have ever been lapped. I've seen factory Rem & Sav bores that looked smoother than the OP's (end to end), not that they shot well with ammo on hand. That said, my .30 cal R-15 has the worst bore I've ever seen. It's obviously hammer forged (had to be cold) and bears linear 'wrinkles' of uniform depth on/in both lands and grooves. btw: I had two from the same source, identically flawed and worthy of a writeup if it was more that just a bad batch of R-15s in .30 RAR. (It does shoot as well or better than I can with factory 125s. :willy_nilly: )

I often wondered if the SS tube of the bore scope ever let me gouge a bore. I now have a certain way of holding it (at 3:00 balancing the light's weight on fingertips) to lessen the chance with the lightest grip. (Blue painter's tape always on the scope's tube.)

To contribute the least bit here, what I've learned over the years with the scope is that the guys are right, above, to say you can't tell much just by looking in there no matter how thoroughly you scrutinize. ;)
 
I often wondered if the SS tube of the bore scope ever let me gouge a bore.

I'm a surgeon by trade and have destroyed several scopes of lesser and much higher quality than a hawkeye, and they are definitely not that strong. Break one in half sometime and see how thin and flimsy the wall is :-). But only do that if you don't have to pay to replace it. :-) I have never seen one that I would be concerned about gouging a bore.

Travis
 
Borescopes can scare the bee jeebies out of you when you look through them. I have seen one holers that have looked like 5 miles of gravel road and some as smooth as a babys bottom shoot like s&%t. All comes down to what the paper target says. I used to jump on the bangwagon of borescoping til I got my ass handed to me about a .25 MOA rifle that looked horrible via the borescope. Sooooo much we DON'T know about how a bullet travels thru the bore
 
Well you are definatly in the class of shooter that gun is borderline, however I dont think your barrel is the issue. When you said that you dont have good lug contact and the crown is rough, that tells me that the smith you used did not take the time to properly chamber/barrel the gun. Honestly, if you have enough meat on the barrel, you could probably pull the barrel, lap the bolt to the action, then set the barrel back and rechamber/recrown and see an improvement. What type of stock are you using on this gun? Who/how is it bedded?
As far as smiths in FL? I dont know of any, however Butch Lambert in this thread is highly thought of, but you may miss out on a season waiting on him as I understand he is backed up. IN LA Ritten Precision is a personal friend of mine and does damn good work, he mostly messes with F Class but will do work for xtc bolt guns. If you really want a local smith check on the US rifleteams site run by Dick Whitting for a recomendation.
 
Thanks for the compliment. I am no longer doing work for the public. Gave up my FFL. Yes I am behind and can't motivate myself to do my own work. I'm really curious as to John's response to you about the smith work that he did for you. I would still like to know if you have even contacted the principles.
 
Butch,
After working with the gun a long time with multitudes of loads/bullets and having no real improvement, I started looking at things carefully in the gun. Some of these factors just slowly turned up. First was the crown, so I recrowned it, with no real change in accuracy. Then I looked at lug matchup, and was somewhat surprised by that in a custom action. I would have assumed it would have either not needed lapping or would have been lapped. I haven't called pierce, but I know that John did not do the work, it was done by his brother Jim. Jim may be great, but I guess when you go to a business like that and are spending $1500 to buy his action and paying him to do the work, you expect the work to be done by the person with whom you talked and who implied that it would be done by. I only found out after the fact when Jim had called me. I'm not a confrontational person at all, and there isn't really any way that I see that I could discuss it with them without being confrontational. I don't want anything replaced or any reparations made, I'm just disappointed in the gun. So i'm just really going to move on with a new barrel. Maybe that won't do any better, but I just want to find a smith who I know will put his best effort in it for every customer and if he says he'll be the one doing it, I can believe that he will. That's just the professional thing to do. I have patients who are very difficult to deal with but when I operate on them, I do the best that I can and the same that I would want done for my family members. Any recommendations of a quality smith would be very appreciated, if you wanted to PM me. The only person fairly close to me that I know of is John Whidden who is a good long range shooter, and has been doing smith work for the past 5 years or so as to my understanding. He's at least close enough that I could go in person and talk to him.

Thanks,
Travis
 








 
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