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

Do new Glock 20's have supported chambers?

Discussion in 'General Glocking' started by rustypigeon, Nov 2, 2012.

  1. rustypigeon


    Oct 30, 2006
    I am thinking of getting a G20 10mm. I would be handloading for it.

    I have read and seen pictures of G20's with unsupported chambers. Is this a problem with the current production G20's?

    If I have to buy an aftermarket barrel, I might decide against getting the G20.
  2. orangeride


    Oct 19, 2011
    My 20sf that is a year old shoots everything fine. You'll find with hot loads you'll still get buldges but you shouldn't get any glock smiles or major buldges. If you want hot loads and super straight cases you'll need an aftermarket barrel. I have one for mine but almost never you it. I do like my lw40 conversion a lot though. You won't get anything aftermarket that's as reliable as he oem.

  3. plouffedaddy


    Apr 1, 2011
    I'm not sure how you'd define 'fully supported' but they are certainly more supported than the older Gen2s.
  4. nraman


    Dec 9, 2002

    The early .40 Glocks left part of the case wall unsupported over the feed ramp. The Gen 4 and the Gen 3 that I have completely support the case wall. Any brass showing above the feed ramp is solid brass.
    If the G20 has a barrel with a chamber like the new .40s, I would trust it to be safe and smiley free with any loads.
    Easy to tell, take an empty 10mm case, measure the depth of the case interior, transfer and mark that dimension on the outside case wall. The mark shows the part of the case that is solid, put the marked case in the chamber with the mark over the feed ramp and check.
  5. Beanie-Bean


    Apr 23, 2011
    Central Texas
    I only ran one box of ammo through my stick barrel before it was replaced with a KKM stock-length barrel. I load my own ammo, so it was important to me to have a barrel which will prevent the brass from bulging out to the point where the rounds won't load or chamber properly.

    Problem solved by using the KKM barrel in the G20SF and a Redding full-length sizing die on the reloading press.
  6. faawrenchbndr

    faawrenchbndr DirtyThirty fan CLM

    Nov 24, 2005
    They do not have a fully supported chamber. I wanted to be able to
    shoot HOT 10mm loads. I bought an STI Perfect 10

  7. alwaysshootin


    Nov 14, 2005
    My last two 3rd Gens had great case support! My 3rd Gen SF, was horrible. Almost as bad as my 2nd Gen. My advice is, if possible, before purchase, ask if you can disassemble before purchase. Take a round with you, and, drop it in the barrel. If support looks good in the feed ramp area, you should be fine. If too much of the case is exposed, count on bulging to occur with hot loads. That's been my experience, and again my SF was so bad, I would not even consider reloading the spent brass.
  8. SDGlock23

    SDGlock23 Glockoholic

    I had a rather new G20sf that I had bought perhaps 6 months ago and it's chamber support wasn't that good. Even loading up medium range ammo with Blue Dot, Unique, TiteGroup and practically all powders would bulge the brass much more than I thought it should. To put it another way, it didn't seem the case bulge should have been what it was given the low-mid 1100's velocity (180gr).
  9. rustypigeon


    Oct 30, 2006
    I just want it supported enough to comfortably shoot reloads. I can't afford to by 10mm factory loads on a regular basis.
  10. F106 Fan

    F106 Fan

    Oct 19, 2011
    Underwood makes some of the hottest 10mm around. They are ok with the Glocks but not the Colt Delta Elite (although they do make a load for it).

    Over on the Reloading forum we just had a long discussion about the 10mm. In the beginning, the load was 180 at 1080. A 180 gr bullet moving at 1080 fps. That is quite light compared to the stuff that Underwood is making. After all, Federal Classic .40 is 180 at 990.

    Who wants to shoot 180 at 1300 just for fun? It might be great for hunting and, MAYBE, SD but it wouldn't be my first choice for punching holes in paper.

    So, when you shoot the uber hot 10mm stuff, leave the brass behind. For your own loads, lighten up a bit and recover the brass.

    This 10mm uber hot reloading reminds me of the old days when folks were hotrodding .357 and .44 mag. They were making fire-breathing rounds but their flinch was so bad even the backstop was safe. If you really like recoil, shoot the .454 Casull for a while. That ought to cure it.

  11. WRGlock33


    May 28, 2007
    Warner Robins, GA
    Here is a pick from my G20 Gen4

    Attached Files:

  12. nraman


    Dec 9, 2002
    A picture is worth a thousand words.
  13. ds7br


    May 10, 2012
    My 3 month old g20 would expand Win factory ammo enough that it would not drop back into the barrel after firing. Since I reload all my ammo I went to a tight chamber Storm Lake, factory length barrel. Problem solved. A quality aftermarket barrel is a must if you want to reload at the pressures the 10mm was designed to handle. If all you want to use are low end factory loads the stock barrel should function fine. I have no problem practicing weekly with my reloads but you may not wish to use high pressure loads. Go with what makes you comfortable and what you enjoy shooting.
  14. Chuck TX

    Chuck TX CLM

    Jul 11, 2003
    Republic of Texas
    I wouldn't shoot hot nuke loads in any stock glock barrel. Have match barrels for that.

    Nice. Got one of those on my list.
  15. rustypigeon


    Oct 30, 2006
    Man, this is a tough one. I'd really like a G20, but $560 for the pistol, another $100 for a caliber conversion kit for my dillon, and another $100-$150 for a barrel is a bit more than I want to spend.

    My local dealers would need to order a G20SF, so I can't really inspect the chamber before I buy it.
  16. michael e

    michael e

    Nov 20, 2010
    My G20 is fine, have loaded to max with blue dot and 800x, no issues with case bulg . Have few other powders to test but all my brass is loaded up at current time .
  17. nraman


    Dec 9, 2002
    Why not get a Gen 4? It has the same grip plus extra back straps and you don't have to special order it.
  18. alwaysshootin


    Nov 14, 2005
    It comes down to priorities! Also a little luck, as far as whether the barrel bulges brass. About as much of a hit, or miss, on whether you can shoot lead out of the factory barrel. The real kicker is the conversion kit for the Dillon! If you had a Lee Classic turret, another tool head is $10.
  19. bushjumper


    Jul 12, 2002
    Arizona, USA!

    Actually the original load was a 200 grain jacketed truncated cone at 1200fps. And followed by a 170 at 1300fps. Both by Norma.

    I'm aware of the 40 G & A and Jeff Coopers idea of the 200gr bullet at 1000 FPS, but the fact is this was not the 10mm as developed by Jeff Cooper and Dornaus and Nixon - it was the 40 G & A obscure wildcat cartridge.

    It was a few years later after the FBI watered it down before it was a 180 at 1080fps.

    Winchester has sold the silvertip since day 1 with a 175 at over 1200fps.

    IMO, if you want a 180 at 1080, you might as well shoot a .40 s&'ll get a smaller and lighter gun. (and cheaper and bigger selection in factory ammo)
    Last edited: Nov 5, 2012
  20. Brian Lee

    Brian Lee Drop those nuts

    Jul 28, 2008
    Up a tree.
    I've shot a lot of hot ammo in my G20 with the stock barrel and never yet saw a smiley mark on any cases. If I ever did, I think I'd assume the ammo was loaded way to hot for safety anyway, and I'd back off a bit on any evil-pressure hand loads that do that.

    From the sound of some of the replies here, I'm wondering if some 10MM Glock barrels have a different chamber diameter than others, or maybe they are not being consistent with the machining of their feed ramps, because some guys are getting bulges from loads than sound weaker than stuff I've fired with no hint of that problem. I've measured the chamber diameters on my own barrels with inside micrometers and I can tell you that my Bar Sto barrels certainly do have a diameter about .005 to .006 smaller than the stock barrel does.
    Last edited: Nov 5, 2012