Quantcast
  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Glock 10mm to .40 S&W Conversion

Discussion in 'Handguns: Autoloaders' started by Fiero, Sep 28, 2004.

Thread Status:
Not open for further replies.
  1. Vitamin G

    Vitamin G Member

    Joined:
    Aug 9, 2003
    Messages:
    934
    Location:
    Monroeville, PA (Home of the Zombies)
    Wait... didn't someone named "Clark" get the reloading forum shut down awhile ago for posting ridiculously dangerous loads at the 1911 forum?
     
  2. JohnKSa

    JohnKSa Member

    Joined:
    Jan 1, 2003
    Messages:
    12,541
    Location:
    DFW Area
    Vitamin G,

    Read post #13 on this thread. It is not intended to be humorous nor sarcastic. Clark does his own version of failure analysis on his personal handguns. While he has explained his techniques with caveats on other threads in this forum, he is often strangely reticent to post disclaimers to go along with his outlandish assertions--which, I might add, are only outlandish if you don't know what his hobby is.
     
  3. D51208

    D51208 Member

    Joined:
    Jun 24, 2011
    Messages:
    88
    Location:
    Oswego
    Blast from the past?

    Hey guys i just got a glock and the ammo is ridiculously expensive! Good thing i hand load. Converting 30-30 to shoot in a 10mm, is it safe and/or better than regular 10mm cases? Whats the process?

    The 40 S&W, if it is the right overall length, can it safely be shot from a 10mm bbl?

    Right now i have 180gr hornady xp bullets and titegroup for powder. I'm ordering lee dies and starline brass sometime here soon. Any suggested loads?
     
  4. GLOOB

    GLOOB Member

    Joined:
    Sep 16, 2007
    Messages:
    5,941
    For those that don't know, Clark TIG welded the ramp of his Glock 22 barrel and recut it to provide full 360 degree support around the entire case, right up to the web. And he's not afraid of voiding his warranty or blowing up the occasional $500.00 firearm in the name of science.

    So if you want to spend the time and money to prove him wrong, then go ahead and do it. Until then, why not just take him at his word? (And stick to SAAMI specs for your own reloading!)
     
  5. Bovice

    Bovice Member

    Joined:
    Sep 27, 2009
    Messages:
    1,593
    For the love of God, don't be hacking up .30-30 brass for a 10mm.

    You need to either pony-up and buy some 10mm brass and load it on your own or trade for a G22. The 10mm they sell off the shelf is extremely similar to .40 S&W but at a much higher price.

    You can't expect to not reload your own ammo when you buy a gun with an obscure chambering.
     
  6. tlen

    tlen Member

    Joined:
    May 12, 2008
    Messages:
    526
    Location:
    Kansas
    Get a LWD 10-40 barrel and use standard G20 magazines. .40 S&W Glock magazines don't fit the G20. No need to change recoil spring; stock works fine. You can get a 6" or a stock length 10-40 barrel. The longer barrel works fine and will give you ~100 FPS more velocity if that is important. With a LWD barrel you can shoot cheaper lead .40 S&W ammo as well.
    The added G20 weight makes shooting .40 S&W feel like 9mm.
     
  7. Fatdaddy

    Fatdaddy Member

    Joined:
    Jun 9, 2008
    Messages:
    251
    My G20c with KKM 10-40 conversion bbl worked flawlessly, same springs, same mags. I bought it because I got tired of losing my 10mm brass in the weeds.
    Plus it looked cool, shiney bbl visible through the factory porting.

    g20ctop.jpg
     
  8. sargents1

    sargents1 Member

    Joined:
    Nov 25, 2009
    Messages:
    188
    Location:
    The Pine Tree State
    Listen to Bovice.

    I am not sure how you think you can make 10mm brass out of 30-30 brass anyway. 10mm has a rimless design (where the case head rim is flush with the sides of the cartridge body) and 30-30 has a rimmed design.

    I doubt you could safely make 30-30 brass into 10mm brass, and even if you could...Why would you when 10mm brass is the SAME price as .40S&W brass?

    Starline Brass 10mm Auto is $85.50 / 500ct.
    (http://www.starlinebrass.com/index.php?cPath=1&osCsid=5bf9adaf2d9e6c8b198fe2c8e2ead65f)

    Starline sells .40s&w brass for $81.50 / 500ct.

    As for shooting .40s&w ammo thru a 10mm Auto barrel...
    It is probably safe (probably being the operative word here).

    10mm runs as high as 37,500psi where .40s&w runs 35,000psi. But automatic cartridges headspace on the mouth of the case rim. Meaning, it is the case rim that stops the cartridge from going too far into the barrel/firing chamber. So you could theoretically chamber a .40s&w cartridge and it might fall too far into the chamber for the firing pin to contact it.

    I have heard of folks doing this, but I will NOT be doing it with my G20. There is no compelling reason to do it, and it may not be safe. I dont know All of the particulars and just because it seems like it should be safe doesnt mean it is.

    Bottom line: If you want to run .40S&W thru your 10mm glock, spend the 125$ - $165 dollars for a Lone Wolf or KKM conversion barrel.

    Now, if there is a Zombie Apocalypse and all I can find is .40S&W ammo, and I MUST use .40 in my 10mm I will do so. But, barring some supernatural emergency I will be using proper ammo.
     
  9. Zak Smith

    Zak Smith Moderator Emeritus

    Joined:
    Dec 24, 2002
    Messages:
    9,037
    Location:
    Fort Collins, CO, USA.
    The right way to do it is to get a .40SW-10mm conversion barrel. It will then headspace properly.

    I have shot some .40SW rounds out of my 10mm Glock (with 10mm barrel) to see what would happen but I recommend against doing that.
     
  10. GLOOB

    GLOOB Member

    Joined:
    Sep 16, 2007
    Messages:
    5,941
    Methinks you didn't read all the posts. Like post #18. I'm pretty sure it CAN be done.
     
  11. R.W.Dale

    R.W.Dale Member

    Joined:
    Oct 14, 2005
    Messages:
    11,379
    Location:
    Northwest Arkansas
    There is much sense here.

    I've personalty not done it but folks have loaded 10mm on 40 brass loading to the same col as 10

    This may seem insane but as Zak points out internal case capacity is the same on a stronger small primed case

    posted via tapatalk using android.
     
  12. Zak Smith

    Zak Smith Moderator Emeritus

    Joined:
    Dec 24, 2002
    Messages:
    9,037
    Location:
    Fort Collins, CO, USA.
    A stronger/heavier case would probably have less internal capacity when loaded to the same OAL.
     
  13. R.W.Dale

    R.W.Dale Member

    Joined:
    Oct 14, 2005
    Messages:
    11,379
    Location:
    Northwest Arkansas
    Agreed. You could easily verify this by cutting a 10mm case down and comparing the case cap in grs of h2o to a piece of 40 brass

    You'll also need to ensure your 10mm 40 conversion barrel is throated to accept the longer than saami col

    You'd definitely want to fine tune and probably dial back a bit. But it wouldn't be the instant KB you'd think at first glance.

    posted via tapatalk using android.
     
  14. Zak Smith

    Zak Smith Moderator Emeritus

    Joined:
    Dec 24, 2002
    Messages:
    9,037
    Location:
    Fort Collins, CO, USA.
    I got KKM to make me a .40SW-10mm conversion barrel. It has enough throat to shoot my USPSA "Limited" .40 rounds, a 180gr JHP at 1.23" in .40SW brass.
     
  15. N43122

    N43122 Member

    Joined:
    Jan 17, 2013
    Messages:
    1
    Hey fellas,

    I've made these insert spacer plates that fit in the Glock 20 magazine that allow a .40 S&W to feed perfectly by pushing the .40 S&W round forward by .095" Keeps the rounds from shifting around inside the mag. Holes are milled into it to still allow mag capacity check. Direct drop in, non-destructive.
     

    Attached Files:

Thread Status:
Not open for further replies.

Share This Page