cocentric barrels

[dmccrerery]

I purchased a 30 cal. straight 1.250 blank barrel and from breach to muzzle it measured .140"+/- off center on a 20" barrel. That doesn't sound " Precision"even tho the company advertises Precision Barrels. I can understand, if this was a barrel made in CHINA, but this is US made.

I understand barrel and bore are not always concentric. (I would think .025 to .050"max. misalignment)
Are there any industry standards for muzzle to breach difference.
Or does each company establish their own acceptable tolerance.

I would like some in put. ( Am I expecting to much )

 

[msinc]

You are definately not expecting too much...but you also probably wont get a cut in stone answer either. I dont know of any standard or tolerance for this. Ideally, you dont want any runout and you want a straight bore too. Personally, I wouldn't bother to cut threads on a barrel with more than .010" over 20 inches. If the bore is straight but you have runout then the result is that the barrel is said to "walk" the shots as it heats up. The hotter the barrel gets as you shoot the more out from center the bullets will go in one general direction. The barrel can be turned down some on a lathe but if the resulting runout is due to stress, which is very likely, then you wont be able to get it all out {unless you are lucky enough to relieve the stress and usually turn alot off the barrel.} I would send it back and ask for a refund then go to a better quality barrel maker. I am unaware of or have never read anything about anyone ever testing the effects of runout...I am sure somewhere along the way somebody has done testing. It seems like since runout is not really something we have to live with {there is really just no excuse for it} then its not worth worrying too much about how it affects performance...bottom line, it's too easy to get a barrel with very, very little to none.

 

[ELR Researcher]

I purchased a 30 cal. straight 1.250 blank barrel and from breach to muzzle it measured .140"+/- off center on a 20" barrel.

How are you understanding and measuring "concentricity"? Are you looking at one end, noting how centered the bore is to the exterior and then looking at the other end and noting that the bore is off center by roughly .140" (over 1/8")? Frankly I have never heard of a commercial barrel that is off center by anything appreciable (a few thousanths).

Pictures would be helpful.

 

[Minesweeper3433]

A gunsmith friend of mine back in Florida has a Douglas .25 straight barrel that is nice and centered on one end but just over .260 off on the other end. He got a great deal on it way back when and has since never gotten around to turning it down for a hunting rifle he wants to make. Makes and interesting conversation piece. If you ordered the blank to make a straight barrel then I would return it but if you planned on turning it down anyway just do so and send it off after turning for stress relief. Just don't forget that by the hole being off center the face of the barrel is not perpendicular to the bore and will need a bit removed to true it up.

 

[dmccrerery]

I really appreciate all the input.
I ordered a new barrel blank from Pac Nor today.
Returning the barrel in question back to manufacture for a refund. I tried working with them to get a replacement, but they blew me off. Said I had a problem. Would not talk to me by phone, always to busy. But D** had time to send insulting email. So much for their "Customer service is our #1 priority"
I have two other barrels made by this company, but you will never hear me say a good thing about them after this.

Thnx Dave

 

[Larryh128]

Customer service usually starts at the top of the chain & works down. It could also be that the boss isn't aware of the issues BUT that's also their fault. At times key players in a comapny change & a great company goes to s--- because persons have been promoted past their capabilities. I'm watching that happen to 2 companies right now. Can't have morons steering the ship or you have another oil spill.