Bad barrel? Borescope vids. Opinions wanted.

[entoptics]

Been having a heck of a time getting my buddies rifle to shoot well, and by "well", I mean MOA or better. Tried a few different bullets, couple different powders, and never could get a repeatable 1 MOA, and generally it's more likely to throw 1.5 MOA, occasionally worse...

I'm fairly certain what I'm seeing on the Teslong can't be good, but wanted a 2nd opinion. The rest of the pipe is nice and smooth, burr and defect free, and cleans easily.

Straight on view of throat area.


Side view of throat area.


This is a drop in Savage prefit barrel, but I won't mention the manufacturer till they have had a chance to address it. 416R, 1:8 5R twist in 7mm-08. Unfortunately it took way too much time and ammo to stumble on to this. Not enough confidence in my buddy's skills, and I was "cobbling together" loads for him with some old brass/bullets/powders, so when things didn't go well, I blamed those factors.

More recently, I went to some pretty extreme lengths to identify the problem, including a skim bed job on his tupperware factory stock, and saw no improvements.

 

[jheilman]

Looks to me the reamer was way off center of the bore. Had this same thing on a new Fierce Carbon Rival, I don't mind mentioning the manufacturer, as I see it as a major mistake which should have never left the shop. They did offer to rebarrel it but I was done with them and lucky for me the store that sold it was willing to refund my funds so that's what I did. I also made a video with the teslong. I think I can still find it if anyone wants to see it. Best of luck with your buddies barrel, must be a good buddy.

 

[shinbone]

The Teslong Borescope is a beautiful thing. Since purchasing one, I always check the bore/throat/chamber before shooting a new rifle for the first time. Results:

I had a new Nosler rifle show a crooked throat just like in your video I sent it back to Nosler, and they re-barreled it for free. This alone paid for the borescope.

Also, had a new MRC 1999 show the same thing, and, same result - sent it back to the maker, and they rebarreled it for free.

In each case, the chambering man ruined a perfectly good barrel.

I am thinking discovering this problem before ever shooting the rifle probably made getting new a barrel easier, because the manufacturer knew it could reuse the barrel. Unfortunately, this is bad news for the next buyer if he doesn't have his own borescope to protect himself.

Include the borescope photos when you communicate with the maker for the first time. It lets them know that you know exactly what the problem is, and thus can't be BS'd.

 

[dennisinaz]

That should be caught before leaving the shop.

 

[MagnumManiac]

This is far more common than you might think.
Yes, it WILL cause an issue having lands in the throat, I have barrels the same, if you, or your friend are unhappy, send it back.
There's no real fix for this, one of my 22-250AI barrels is the same, .0075" off the bore centreline…it happens.

Cheers.

 

[FEENIX]

Been having a heck of a time getting my buddies rifle to shoot well, and by "well", I mean MOA or better. Tried a few different bullets, couple different powders, and never could get a repeatable 1 MOA, and generally it's more likely to throw 1.5 MOA, occasionally worse...

I'm fairly certain what I'm seeing on the Teslong can't be good, but wanted a 2nd opinion. The rest of the pipe is nice and smooth, burr and defect free, and cleans easily.

Straight on view of throat area.


Side view of throat area.


This is a drop in Savage prefit barrel, but I won't mention the manufacturer till they have had a chance to address it. 416R, 1:8 5R twist in 7mm-08. Unfortunately it took way too much time and ammo to stumble on to this. Not enough confidence in my buddy's skills, and I was "cobbling together" loads for him with some old brass/bullets/powders, so when things didn't go well, I blamed those factors.

More recently, I went to some pretty extreme lengths to identify the problem, including a skim bed job on his tupperware factory stock, and saw no improvements.

Contact the pre-fit barrel manufacturer and share your findings.

 

[parshal]

I've had tack drivers that looked like that. But, yours doesn't shoot and you've tried a whole bunch of stuff so I'd be asking for a replacement.

 

[ARlife4me]

When checking oal against this type of clambering can it provide irregular results? Another question, was it throated for a specific bullet at a specific jump?

 

[RuninL8]

I hate to tell you but, that rifle will never shoot well. That's a crooked chamber. One of the reasons I won't even offer the service to my customers.

 

[entoptics]

When checking oal against this type of clambering can it provide irregular results? Another question, was it throated for a specific bullet at a specific jump?

This occurred to me last night, and I just checked my spreadsheet, and sure enough, considerable deviation in CBTO measurements using the Sinclair tool (ES of 0.014" on the 140 SBDII). Crap. Can't believe I let that slide past without noticing it a year ago...

The barrel is an "off the shelf" prefit, so presumably standard SAAMI chamber, and based on the BTO measurements, I have no reason to believe otherwise.