Gunsmithing borescope photo question

Jrb572

Full Member
Full Member
Minuteman
Supporter
  • Dec 7, 2008
    3,118
    1,693
    Missouri
    Does this look ok? I do not know anyting about riffling a barrel. Its a proof 308 chambered by proof. It shoots good
     

    Attachments

    • Snap_001.jpg
      Snap_001.jpg
      309.8 KB · Views: 161
    Yeah if most folks would look at a 6.5 Creedmoor at 1500 rounds they'd want to throw it out when the barrel would probably keep shooting 1000-1500 more.
     
    This is the equivelent of sticking your head up your car’s exhaust with a flashlight trying to understand how it runs.

    Studying this would usually require a host of barrels, in various degrees of wear that can be identified by the type of wear they have and understanding what that means so you can compare the visual to what the issue is, vs

    taking a newish barrel and having no background and trying to figure out what you see

    we have models on how to study and learn by example, not seeing how this approach is the same or works. But that is me, then again I shoot my stuff until it stops and then I change it,
     
    • Like
    Reactions: Nik H
    Things to look for are excessive copper fouling, like copper plating that won't easily clean out. Usually caused from deep machining marks in the throat or button chatter on factory grade barrels (Savage is a big offender here, but not alone).

    Can also look for uneven rifling start, and/or off-center free-bore. Doesn't necessarily mean anything, but something to look for if accuracy can't be fixed. Indicative of a bad indicating job on the manufacturer's part.

    Obvious defects in the rifling, bulges, flattened lands, etc... Can sometimes cause issues. Internal burrs, especially on AR's where there's a gas port...

    Totally roached burned out firecracked throats. This is a slow process and it shows up usually around 500-1000 rounds into a barrel and just keeps getting worse. When accuracy/velocity drops off is totally dependent on caliber, rate of fire, loads, heat, etc... Hard to tell anything from this because sometimes they look ugly as hell but still shoot fine. For example, I saw it starting on my last 6.5cm barrel about 800 rounds in, and it lasted til 3200 before I started getting fliers ugly enough I stopped shooting matches with it.

    Good way to look at rings in the chamber from manufacturing goofs.


    That all said... Very rarely is it a useful tool to look at something and say "that won't shoot because of XXX". I've seen chamber jobs so off center the rifling (or a shallow part of it anyway) went all the way back to the neck on one side of the free bore. Rifle shot fine. IMO You'll learn more from slugging a bore, and even more yet from shooting the rifle.

    ETA: Carbon rings! actually a useful endeavor to find them and see if they're gone after cleaning. They'll damage bullets, spike pressure, etc...
     
    • Like
    Reactions: GONE BAD and Jrb572
    Once again that's why I asked if it looked ok. I said it shoots good. I didn't say oh my god the sky is falling this barrel is a piece of crap. Just looking for a professionals opinion.
     
    It’s not the question or the drive to learn, it’s the approach

    In this case i would say more upfront is better, by that I mean over explaining what your goals are vs just saying,

    look i have a cheap Chinese borescope what am I looking it with a picture attached

    Instead, being proactive to help educate vs creating a post easily dismissed with a Here we go again

    Usually we have to draw out the situation in more detail, what I am saying is, for anyone reading this, in cases where the post can go in a variety of directions, say more instead of leaving it wide open.

    I get it, worthwhile endeavor trying to learn, just be aware of the pitfalls of these types of posts
     
    Can also look for uneven rifling start, and/or off-center free-bore. Doesn't necessarily mean anything, but something to look for if accuracy can't be fixed. Indicative of a bad indicating job on the manufacturer's part.

    ...
    .

    ...


    That probably should have been my original question does this rifling start uneven and if it's not causing an accuracy problem should I even care.