Privacy guaranteed - Your email is not shared with anyone.

Welcome to Glock Forum at

Why should YOU join our forums?

  • Reason #1
  • Reason #2
  • Reason #3

Site Description

reaming an aftermarket barrel

Discussion in 'Gunsmithing' started by ssgrock3, Apr 20, 2010.

  1. ssgrock3


    Aug 10, 2003
    Yukon, Oklahoma
    ended up with a barrel purchased online that is match tolerence. Would like it to be more glock mfg tolerance. Can this be done by my non-gunsmith self or who where can do it?
  2. eisman

    eisman ARGH! CLM

    Jul 28, 2002
    Moving Target
    What are you asking?

    Match Grade is used to refer to the tolerance (uniformity) of the barrel, measured between the lands. Do you really want to rebore the barrel to a looser tolerance?

    If so, anyone can do this. Get a cordless drill and a bit, and just go to town.
    Last edited: Apr 20, 2010

  3. Orion's Belt

    Orion's Belt Boost Addict

    Feb 2, 2010
    Pittsburgh, Pa
    If you want a barrel with Glock tolerance, why don't you stick with the stock barrel?
  4. Brian Lee

    Brian Lee Drop those nuts

    Jul 28, 2008
    Up a tree.
    When barrel makers sell "match fit" barrels they are talking about the fit of the barrel hood into he slide, and NOT just referring to a (supposedly) better & smoother bore. On Glocks, it's also about the side-to-side clearance where the rear barrel protrusion goes into the groove in the breech face (which always matches the width of the cartridge) I fitted mine myself because I am a tool & die maker and had access to better machine shop equipment than 99 percent of all gunsmiths do.

    I only needed to remove a little bit of steel from the rearward protrusion that fits into the breech face of the slide, and did it with a surface grinder. If a person was really careful, I suppose it could be done with a bench type belt sander, but it wouldn't be as nice a job, and there would be a lot more risk of taking off more material than you wanted to. Personally I think I could have done it with a file and done a nicer job than a belt sander would do, but I have a lot of metal working experience, so it's easy for me to say that.

    The thing about buying match barrels that require fitting is that what you pay for someone else to do the fitting could easily be a lot more than it's worth to you, considering that you could have just bought a "drop in" barrel in the first place.

    The other thing about match barrels is that the chamber diameter might be about .003 to .004 smaller than a Glock chamber, (notice that I said CHAMBER diameter and NOT bore - a match bore isn't any smaller) and you'd need a really nice lath to change that. Don't let some "butcher smith" with a table top Unimat or Harbor Freight lath try it or they'll probably just screw it up for you.

    There is NEVER any difference in the land/groove diameters of the bore in a match grade barrel. At least not in the sense that you want to ream it out bigger. Just better smoothness and better consistency - if your lucky. The better bore tolerances of a match barrel are not something you'd change to get it fitted to your gun. It's all about having a barrel that does not have any wobble or slop at the back end when the gun is locked into battery. That's why they fit them to individual guns - to compensate for small variations in the slides.
    Last edited: Apr 20, 2010
  5. ssgrock3


    Aug 10, 2003
    Yukon, Oklahoma
    I should have said are correct. What I want is a standard rifled barrel that has a liiiiiitle bit looser tolerance than the one I have. I reload, they are good but some barrels are finicky and will not feed every bullet profile I can come up with in a 9mm. My barrel is very tight, I would like it to relax a little.

    to the poster asking why go aftermarket or looser tolerance. I shoot lead also, so prefer a standard rifled barrel over the stock polygonal version.
  6. ssgrock3


    Aug 10, 2003
    Yukon, Oklahoma
    shooting lead and a variety of reloads.
  7. Jager1147


    Nov 17, 2002
    Ronkonkoma, NY

    It's always better to try and solve the problem by altering the ammo before the gun, especially since you reload. I would highly recommend 2 dies, and to use both:

    1) the Lee U-Die (the one from EGW is ground to get closer the shell plate)

    2) The Lee Carbide Factory crimp die (gives the entire case a full length resize while taper crimping as a seperate step)

    and of course experiment with different cartridge OAL to achieve reliable feeding.
  8. ssgrock3


    Aug 10, 2003
    Yukon, Oklahoma
    true statement, but I think this might be an old federal barrel, and may just need cleaned up.

    You guys are right, always better to work on the ammo. Truth be known I have only had one round jam, but it was jammed bad enough to lock the gun up completely. I would imagine I didn't seat this to total depth on my down stroke, but I have a low tolerance for this sort of thing. I dug a few bags of ammo that I load several years ago out for fun, probably a newbie mistake. Thanks for all the help guys.