10mm magnum conversion

Andy1

New member
Is it possible to convert a Glock 40 to 10mm Magnum?

Would the longer cartridge fit in the magazine? If not, could it be modified to fit or just a no-go? An empty magnum case is slightly shorter than a loaded auto round, 1.255" vs 1.260", so a spent case would clear the ejection port. But would a loaded magnum round clear the ejection port?

I ask because I'd like to get a 6.5" threaded KKM barrel. But if I'm going to the expense of that, maybe I can do the conversion also. The gun is used as a hunting sidearm or range practice.
 
Yeah the 10mm Mag is 5-6mm too long. Also why would you want to trim the 10mm Mag to 10mm Auto length when 10mm Auto is the parent case of the 10mm Mag?
 
No, magazine isn't long enough.

Correct.

Even if you had the chamber of the G40's barrel reamed to 10mm Magnum specs, the longer cartridge wouldn't fit the Glock 10mm magazine. At best you'd have a 1-shot Wonder.

However, converting a 10mm revolver to 10mm Magnum is easily accomplished be reaming the chambers of the cylinder to the Magnum's specs, as was done on many S&W 610 revolvers by wheelgun 'smiths like Hamilton Bowen and Gary Reeder.

Especially convenient is that the 10mm Magnum cartridge will fit the same moon clips as the 10mm AUTO and the .40S&W, and once a S&W 610 is so converted (or similarly, one of Ruger's DA 10mm wheelies), you've got yourself a 3-in-1 fun gun.

:cool:
 
Andy1, if you're interested in a semi-auto in 10mm Magnum keep a lookout for a LAR Grizzly in 10mm Mag or a AMT/IMI Automag IV in 10mm Mag, I also think Wildey made some 10mm Mag pistols/barrels too IIRC. The Automag IV might be the more affordable/available option.
 
Gotta admit - I'd never heard of 10mm Magnum until now!

A bit dated, but here's gun-scribe John Taffin's write-up on the 10mm Magnum:

http://www.sixguns.com/tests/tt10mag.htm

The 10mm Magnum has definite applications as a hunting pistol and a long range silhouette pistol. Shooting informally at long ranges of 100 to 200 meters and using rocks as targets convinced me of this. Anything the .41 Magnum can do, the 10mm Magnum can also do and perhaps do it even a little faster and a little better. That is a tough confession for an old sixgun man to make.
 
For 10mm Mag, your best bet currently is to get a GP100 10mm or a Blackhawk 10mm and have it reamed out for 10mm Mag. That said, a .41 mag would probably be better for several reasons, one its cheaper because you can just buy a .41 and not have to worry about permanently changing (and paying for) an existing 10mm and two, in general .410" bullets are stronger than .400" bullets. Because most .400" JHP bullets are still designed around the .40 S&W, pushing them faster than intended isn't a recipe for success, penetration gets bad because the bullets don't hold up to the velocity.
 
"...never heard of 10mm Magnum..." Another answer to an unasked question.
Loaded ammo doesn't appear on either Midway's or Graf's sites. Graf's shows Starline brass at $26.79 per 100(not bad). No listing of anything 10mm Mag by Midway.
And it's the loaded OAL that matters.
 
"...never heard of 10mm Magnum..." Another answer to an unasked question. Loaded ammo doesn't appear on either Midway's or Graf's sites. Graf's shows Starline brass at $26.79 per 100(not bad). No listing of anything 10mm Mag by Midway.

:rolleyes:

Wow, all of 2.5 seconds of google-fu turned up in stock 10mm Magnum factory ammo from Double Tap and Reed's Ammo & Research.

Here's DT's 10mm Magnum page. One load is a special 230gn hard cast slug.

http://www.doubletapammo.net/index.php?route=product/category&path=125_395

Reed's 200gn load lists at 1620fps/1165fpe

https://shop.reedsammo.com/10mm-Magnum-200g-Hollow-Point-1620FPS-10MMMAG200X.htm
 
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