simple solution for chamber polish and cleaning?

Discussion in 'Gunsmithing' started by ajhardle, Sep 22, 2012.

  1. ajhardle

    ajhardle Well-Known Member

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    All my best groups came from unfired, and I'm sure I just found why. Every case, after firing has a pinpoint dent near the shoulder. I'm guessing debree is now bedded pretty firmly in the chamber after a couple hundred firings. I actually noticed it on a few reloads months ago, and assumed it was a dirty sizing die. I cleaned it up and forgot about it 'til now. Any suggestions to get it out?
     
  2. SidecarFlip

    SidecarFlip Well-Known Member

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    May or may not work....

    I had a 308 FL sizing die (RCBS) that I stuck a case in real bad and had to resort to serious removal as in digging it out. It was a bit chewed up in the bore so I took a respectively sized bore mop and some Clover lapping compound, put some on the mop and chucked the mop in my trusty 18Volt Dewalt drill and went at it on the die, polishing it in a cross hatch fashion (like a cylinder bore). It's actually better than new now. like a mirror inside. Added benefit is the die sizes easier (though I don't forget to lube cases) either.....

    That might work in your chamber as well.
     

  3. ajhardle

    ajhardle Well-Known Member

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    I tried a similar method with polishing compound. I will have to wait to shoot it to see if it helped. If not, I may try lapping compound. I was a little hesitant to put lapping compound in there. I suppose it would take more effort than I am willing to put forth to change chamber dimension, correct?
     
  4. SidecarFlip

    SidecarFlip Well-Known Member

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    Absolutely. Lapping compound, especially in finer grits, is nothing more than a final polish. It won't dimensionally change that chamber. It will, however, smooth tooling marks. It might actually make extraction and chambering easier. No guarantees but it might.

    After I 'operated' on the die, I ran a freshly deprimed once fired and tumbled bright cartridge through the die and had serious lines imparted in the brass from my 'operating' on the die. After running the mop/lapping compound in the die bore a minute or two, I tried another cartridge and it resized clean and free of marks.

    I'd never recommend it as a regular cleaning regimen but one time, no issue.

    Make sure whatever you use, you clean it all out of there. I clean my bores and chambers with non-chlorinated brake cleaner is spray cans. It's haf the price of the gun store stuff and I think the only difference is it don't have a citrus smell.

    I got tuned into brake cleaner because I shoot indoor target pistol, mostly tricked Rugers and Rugers are a royal PITA to strip so SOP is to pull the grips and hose 'em down with brake cleaner. I do my Kimbers and Wilsons the same way.
     
  5. barnesuser28

    barnesuser28 Well-Known Member

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    SidecarFlip, would putting a little but of iosso on a bore mop and attaching it to a drill work? If so, i might try it in my dads 338 Lapua as it think it has a rough chamber.
     
  6. SidecarFlip

    SidecarFlip Well-Known Member

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    It should. Polishing compound and lapping compound is basically the same, just lapping compound suspends the abrasive grit in a grease (pertoleum) base.

    ...and we all have bore mops or at least most of us........

    Just take your time and don't crank up the drill motor rpm, why I use my DeWalt. It's varible speed.

    Don't fprget to clean everything well afterward.

    Wish I was your age again, I'd do a bunch of stuff differently.
     
  7. barnesuser28

    barnesuser28 Well-Known Member

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    Ok, i will probably give it a go after tomorrows shooting session. How did you attach it to your drill?
     
  8. geargrinder

    geargrinder Well-Known Member

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    Careful with the polishing. The brass needs something to grab onto. A very smooth chamber transfers that pressure to the lugs and abutments. It will behave the same as a hot or overpressure load.
     
  9. barnesuser28

    barnesuser28 Well-Known Member

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    i will make sure to go easy on the polishing. How long do you think i should go?
     
  10. SidecarFlip

    SidecarFlip Well-Known Member

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    A minute at the maximum. Then inspect and clean. I use a mop screwed into a brass adapter screwed into a brass cleaning rod chucked in the drill motor.

    The finer the grit, the less agressive the cut. Brass polishing solution is very fine, not at all agressive so you should be good to go.
     
  11. Edd

    Edd Well-Known Member

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    The first thing you need to do is determine what the "it" is that you are trying to get out. Once you know that you can decide the next move.
     
  12. ajhardle

    ajhardle Well-Known Member

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    Well, 600 grit lapping compound didn't have any affect. I guess it's off to a gunsmith to run reamer through it.
     
  13. SidecarFlip

    SidecarFlip Well-Known Member

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    Must be a serious defect in the wall....

    Just be apprised that reaming the chamber might impart machining marks depending on the chamber shape, how it's reamed and the condition of the cutting edges as well as the lubricant used.

    Curiously asking, can you visually see the inclusion or can you just feel it? That bore scope I bought a while back (that about broke my wallet) makes seeing what you normanlly can't see, easy to see.
     
  14. ajhardle

    ajhardle Well-Known Member

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    I can neither see or feel inside the chamber. It's a 223, so I can't reach a finger in their, and I can't get light at the right angle to see up near the shoulder on the barrelled action. But, I do see the dent on every single piece of fired brass I pull from this chamber. It shoots better than anything else I've owned, when using new brass.