New barrel odd oberservation.

[paulT]

in process of running in a new 32in Heavy palma contour barrel for my FTR rifle and have noticed when i look along length of barrel from chamber to bore that there appears to be 3 uniform rings which are visable however upon inspection with borescope with rifling seems fine the first ring is 2 inches from crown next is another 2 inches then third another 4 inches appart, has anyone encountered this before.

 

[watercam]

Picture might be handy...

 

[Raythemanroe]

Not very uniform contouring



Ray

 

[ridgeway]

Put that barrel in a barrel spinner and finish it down to 600 or 800 grit. Probably just the rough contouring?

 

[paulT]

Thanks for replies, would ununiform barrel contouring impair on accuracy? will post few picks when i get camera running.

 

[jim_k]

Concentric rings visible as a darkening of the light shining through the bore usually indicate that the gun was fired with a partial barrel obstruction, such as a cleaning patch, which caused permanent deformation in that area. If that happened, the rifle will probably not shoot well. If it shoots well, I don't know what to tell you.
Jim

 

[BoydAllen]

I have done it again, skimmed to quickly. If you are sure that nothing that you have done could have produced what you see, you need to call the barrel maker, who will probably want it returned for inspection, and possible replacement.

 

[LawrenceHanson]

I have read the original post several times and it is not quite clear to me whether the observed rings are located on the outer surface of the barrel or if they are within the bore. If they are within the bore I would agree with jim_k in that they were likely formed by firing with obstructions in the barrel. And if this is indeed the case, chances are they cannot be seen through a borescope but you may be able to feel them with a tight fitting patch on a cleaning rod.

Not trying to create any confusion with this post. Hopefully the O.P. can clarify the situation and get the responses on target.

 

[gotcha]

OP states bore & rifling look fine through bore scope. Just a guess but the small rings on outside of barrel could have been caused when stopping and starting lathe to accommodate change in feed rate to maintain proper contour. I'd inquire of mfg. to verify...... Shoot it 1st. It might be a hummer.