Barrel chamber scratches

Discussion in 'Gun Project Questions & Gunsmithing' started by Lucky Shooter, Sep 21, 2019.

  1. Lucky Shooter

    Lucky Shooter Gold $$ Contributor

    Joined:
    Jun 14, 2014
    Messages:
    178
    I finished a couple of new barrels---22-250---and have shot both a few times, both
    appeared to be good shooters.

    In the meanwhile I bought a Lyman bore scope and have found scratches in both
    barrels-----top of the lands in the throat area----only.

    I originally thought this had occurred when reaming the chambers but now am pretty
    much convinced I did it twirling a bore brush to clean out in front of the chamber neck.

    I have another barrel which will be rechambered so I decided to repeat the twirling on this chamber.
    Scratched it also----convinced me that I caused the problem with a bronze bore brush. I don't have time to spend figuring how bronze will scratch stainless-----just want to move on to the correction
    of this problem.

    I'm sure I can remove these scratches by reaming the chamber a bit deeper----and correcting the tenon and headspace. This wouldn't be new to me but I'd like to avoid, if possible, the extra work.

    Anybody here have an easier solution for this ?

    Will appreciate any ideas on this.

    A. Weldy
     
  2. Stan Taylor

    Stan Taylor Gold $$ Contributor

    Joined:
    Sep 2, 2017
    Messages:
    1,242
    You think you scratched the barrel with a bronze brush humm.
     
    hogpatrol, butchlambert and tmwinds like this.
  3. Lucky Shooter

    Lucky Shooter Gold $$ Contributor

    Joined:
    Jun 14, 2014
    Messages:
    178
    I'm depending on logic for my suspicions.

    The sacrificial chamber didn't show any such scratches before
    twirling the brush----showed scratches after.

    I'm surprised at this but its all I can conclude.

    At this point I just want get out of this situation and figure how it
    happened later. Just looking for other ideas to remedy this.

    A. Weldy
     
  4. Stan Taylor

    Stan Taylor Gold $$ Contributor

    Joined:
    Sep 2, 2017
    Messages:
    1,242
    Did you twirl this brush by hand or on a drill just curious.
     
  5. Lucky Shooter

    Lucky Shooter Gold $$ Contributor

    Joined:
    Jun 14, 2014
    Messages:
    178
  6. Doug Beach

    Doug Beach Silver $$ Contributor

    Joined:
    Mar 22, 2015
    Messages:
    234
    Why do you want to get rid of the scratches?
     
  7. mike a

    mike a 6BR Rocks Gold $$ Contributor

    Joined:
    Dec 30, 2015
    Messages:
    877
    Get a refund on the borescope, buy more bullets and have fun. Mike
     
    6MMsteve, shoobe01, hogpatrol and 4 others like this.
  8. Spotshooter

    Spotshooter

    Joined:
    Dec 26, 2018
    Messages:
    14
    Did you use range rods to indicate the barrel, they can scratch the top of the lands if you don’t smooth the ends of the bushings.
     
  9. Lucky Shooter

    Lucky Shooter Gold $$ Contributor

    Joined:
    Jun 14, 2014
    Messages:
    178
    Doug, I have no such experience to guide me but am concerned that the scratches
    will cause more copper fouling----just a suspicion on my part.

    Mike, I wish I could get comfortable with your approach----not looking forward
    to putting two barrels back in the lathe.

    Spotshooter, I indicated in the estimated throat with a Grizzly Rod, followed by a long stem indicator.
    The pilot bushing was checked with a magnifying glass with no sign of rough spots.

    On both barrels, these scratches were on the sloped portion of the throat.

    Have considered shooting both barrels to check for excessive copper fouling.

    A. Weldy
     
  10. cem

    cem

    Joined:
    Jul 19, 2012
    Messages:
    32
    Should be no news that a bronze brush will scratch. Wilson Combat sells bronze chamber brushes in pistol calibers that are intended for quick and dirty keep it working as cleaning the chamber over lunch during a high to very high round count training session. The Wilson Combat brushes have a reputation for very visible scratches but that can be what it takes to keep up with high round count exercises on the square range or down range when rushed. As to how, it's not impossible to polish a diamond but the polishing compound is worn away faster than the harder diamond. Then again it's perfectly possible to polish a chamber, Zediker goes into it for gas guns and J.B. compounds are useful for cleaning, polishing and even for hard fitting. Then again one of the MacMillan family was death on J.B. in his barrels. There are those who suggest breaking in a barrel by rolling a bullet in grit. Myself if I were really worried I'd probably get the barrel really clean, easier now than later, and apply a ceramic bore coating. Properly applied and cured the ceramic bore coatings go a long time between bore cleanings. Then again I might coat one barrel and shoot the other just to see.
     
  11. Stan Taylor

    Stan Taylor Gold $$ Contributor

    Joined:
    Sep 2, 2017
    Messages:
    1,242
    Does that Lyman borescope have a little screen that you can see the scratches if so would be nice to see pictures of your issue I think you would get better answers to your concern of what your seeing.
     
    butchlambert and oht like this.
  12. Lucky Shooter

    Lucky Shooter Gold $$ Contributor

    Joined:
    Jun 14, 2014
    Messages:
    178
    Here's a shot of all four land tops in the throat in one barrel.

    Sorry, pictures didn't work.









    A. Weldy
     
  13. Shawnba67

    Shawnba67 Silver $$ Contributor

    Joined:
    Aug 22, 2016
    Messages:
    1,020
    Shoot it ten times and clean and recheck.
     
  14. Stan Taylor

    Stan Taylor Gold $$ Contributor

    Joined:
    Sep 2, 2017
    Messages:
    1,242
    Here is pics of Lucky Shooters throat definitely not from a bronze brush have it it guys I think a dull reamer at the throat unless chamber rpms is a factor may be wrong.
     

    Attached Files:

    mrjdasr and hogpatrol like this.
  15. DaveTooley

    DaveTooley Silver $$ Contributor

    Joined:
    Sep 29, 2008
    Messages:
    766
    Scratches may be a bit extreme. Slight blemishes is more appropriate. For 40+ years I've used nothing but brass brushes and clean frequently. I've never hurt a barrel. After about 300 rounds I intentionally twist my brass bore brush in the neck/throat area to manage the carbon build up at the end of the neck. Never lost a minutes sleep over it.
    Take a polished piece of barrel and run the brush over it. Marks yes, scratches not really. They will disappear in just a few rounds.
     
  16. shortgrass

    shortgrass

    Joined:
    Aug 8, 2010
    Messages:
    1,622
    I'd have to go with a dull reamer along with a possible poor fitting pilot.
     
    butchlambert and Stan Taylor like this.
  17. DaveTooley

    DaveTooley Silver $$ Contributor

    Joined:
    Sep 29, 2008
    Messages:
    766
    Yep reamer marks. probably dull, could be feed rate, could be chip load, could be lubrication.
    Could be all the above.
     
    butchlambert and Stan Taylor like this.
  18. Dusty Stevens

    Dusty Stevens COVFEFE- Thread Derail Crew Gold $$ Contributor

    Joined:
    May 8, 2014
    Messages:
    13,438
    Dave and stan have the answer above. Check that reamer. If youre manually oiling the reamer and cleaning it (not flush system) take shorter passes on the last 1/4” or so. Clean the reamer more often.
     
    DaveTooley, Ggmac and Stan Taylor like this.
  19. AckleymanII

    AckleymanII Silver $$ Contributor

    Joined:
    May 11, 2006
    Messages:
    2,639
    I let Lucky Shooter borrow my brand new reamer. RPM he used was 70. Dark sulphur cutting fluid.

    I have never seen this in one of my chambers...mind blower for sure.
     
    Stan Taylor likes this.
  20. Dusty Stevens

    Dusty Stevens COVFEFE- Thread Derail Crew Gold $$ Contributor

    Joined:
    May 8, 2014
    Messages:
    13,438
    Chips do damage like that- not necessarily the reamer
     

Share This Page