Got the 10mm Glock Bug!

[Dwe]

Wow
After Shooting my Dan Wesson Custom 10mm Silverback this fall, I really got the bug.
Being a Glock fan as well, I bought a Gen 4 G20 top end for my G41 and a SL 10mm conversion barrel for my G30sf which after shooting has been splitting time with my 1911's as my EDC.
Then as fate would have it, I read about the G40 MOS.  And I began to search.
Glock 40's are kinda hard to find.  However I won one on GB for free shipping and no Cc fees.
Better start reloading some max loads.
Well, I picked it up tonight.
What a beast!
Can't wait to give it a try.
Anyone here have both a G20 and/or a G40?
Opinions would be appreciated !
My G41 with a G20 top end.



My new G40

[Captain O]

You'll like the G40, (though the top does not exchange with the G20). You'll find the G40 is the "cat's pajamas" when it comes to working in the field with a semiautomatic pistol. The only thing that could improve the handgun would be a 7" custom Glock barrel with polygonal rifling. this would increase your velocity while making the pistol even more muzzle heavy. This is not altogether negative as it tends to further mitigate recoil, permitting you to quickly return to your target.

Polygonal rifling "squeezes" every bit of velocity from your ammnuition,  increasing range, energy and flattening trajectory.

Enjoy your new Glock. (I'm certain you will).

[Gen4G20]

I love my G40, I actually sold my G20 since I bought the G40.  I installed a Trijicon RM07 on top of mine and am shooting underwood 200gr xtp at 50 yards and it is deadly accurate. I did this because I am taking it hunting with me. I also shot some buffalo bore 220gr hard cast and they were very accurate. 

[sstewart]

Why wouldn't it exchange? I put a G 20 topend  on my G 40 frame just fine.
It was my understanding that the frame is the same.

[Dwe]

You'll like the G40, (though the top does not exchange with the G20). You'll find the G40 is the "cat's pajamas" when it comes to working in the field with a semiautomatic pistol. The only thing that could improve the handgun would be a 7" custom Glock barrel with polygonal rifling. this would increase your velocity while making the pistol even more muzzle heavy. This is not altogether negative as it tends to further mitigate recoil, permitting you to quickly return to your target.

Polygonal rifling "squeezes" every bit of velocity from your ammnuition,  increasing range, energy and flattening trajectory.

Enjoy your new Glock. (I'm certain you will).

Thanks.  However the gen 4 G20 slide is completely compatible with both the gen4 G40 and G41 frames.

Why wouldn't it exchange? I put a G 20 topend  on my G 40 frame just fine.
It was my understanding that the frame is the same.

You are correct Sstewart!
I used my Glock 20 top end on my gen4 Glock 41 last week at the range.
It worked perfectly.

The G40 and th G41 Frames are Identical.



G20 slide on G40 frame

[sep]

Nice pistol! I had a G20 but sold it to a co-worker when I ordered the G40. Since receiving my G40, I installed all the aftermarket parts I had in my G20 and she runs fine.

I installed a Dawson Precision adjustable rear sight and fiber optic front sight, stainless gen 4 RSA, 6 inch KKM barrel and the best upgrade of all, the Zev Tech Fulcrum Trigger. It's still not as light or good as the Powder River Precision triggers I have on my XDMs in 9mm and 45 ACP but it's a big improvement.

Before I went with the Zev Tech, I did what some refer to as a 25 cent trigger job on my G20, when that didn't satisfy, I tried a Ghost 3.5 connector which helped but still didn't give me quite what I wanted. The Zev Tech is probably about as good as this Glock trigger will get. It's a big improvement from the stock setup and makes accurate shooting easier for me.

I'd like to see Glock build a hunting G40 which removes both internal safeties and just leaves the trigger safety. I think that would help the trigger even more.     

[DM1906]

Why wouldn't it exchange? I put a G 20 topend  on my G 40 frame just fine.
It was my understanding that the frame is the same.

The Glock 20, 21, 40, 41 share the same frame, within their respective generations (except there is no Gen3 40 or 41). None of the Gen4 (full size) slides fit any of the Gen3 frames (without significant -ill-advised- modification).

[MOFun]

First post on this forum. 
I know it's an old thread, BUT...
I was unsure of the frame size of the 40/41 MOS's. Was it new or not?  This info about frame/slide swap fitting seems extremely obscure for the new MOS models (to me).  So, Thank you members of 10mm-firearms! Now that I know, my next purchase will be the G40 MOS.  One question, any (potential) extraction issues going from 10mm to .45 with just a conversion barrel swap?or vice versa just for knowledge.

[4949shooter]

Very nice Glock pistols.

My 2011 Gen 3, and Gen 4 barrels love Underwood Ammo.

Enjoy..

[sstewart]

First post on this forum. 
I know it's an old thread, BUT...
I was unsure of the frame size of the 40/41 MOS's. Was it new or not?  This info about frame/slide swap fitting seems extremely obscure for the new MOS models (to me).  So, Thank you members of 10mm-firearms! Now that I know, my next purchase will be the G40 MOS.  One question, any (potential) extraction issues going from 10mm to .45 with just a conversion barrel swap?or vice versa just for knowledge.

Frame is the same.
There is NO 10mm to 45 conversion barrel (only 45 to 10mm) so yes extractor issue
You need complete 45 slide & barrel


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[Grizdad]

Not sure what the Captain is referring to.  I took my G40 MOS slide assy. and put it on top of a FDE G21 frame.  Both Gen. 4 models and can't tell any difference in the frames or internals.

[DM1906]

First post on this forum. 
I know it's an old thread, BUT...
I was unsure of the frame size of the 40/41 MOS's. Was it new or not?  This info about frame/slide swap fitting seems extremely obscure for the new MOS models (to me).  So, Thank you members of 10mm-firearms! Now that I know, my next purchase will be the G40 MOS.  One question, any (potential) extraction issues going from 10mm to .45 with just a conversion barrel swap?or vice versa just for knowledge.

Frame is the same.
There is NO 10mm to 45 conversion barrel (only 45 to 10mm) so yes extractor issue
You need complete 45 slide & barrel


Sent from my iPhone using Tapatalk

Correct. .45 -> 10mm = OK. 10mm -> .45 = No.

The (only) reason is the slide. The difference between the slides is the breach channel width (and FP safety, which is not an issue). They accommodate the case head width, which makes the 10mm slide too narrow to accommodate a .45. The Glock barrel hoods, OEM or aftermarket, are machined to fit their respective slides. The .45 barrel will install and "look" fine, until the action is closed (and it won't). The external dimensions of the barrels are otherwise identical. The 10mm slides can be milled, of course, but it's less than practical.

When converting a .45 to 10mm with only a barrel swap, there is no issue with the extractor, as long as it's LCI. Non LCI extractors should be upgraded, or there will be issues. It's no more complicated than that.

As far as crossing the generations goes, it is also simple. All Gen 3 slides fit Gen 4 frames (20, 21, 40, 41). None of the Gen 4 slides fit Gen 3 frames. The difference is ONLY the diameter of the RSA, and the accommodations for it. The Gen 3 frame can be modified to accommodate a Gen 4 slide by increasing the radius of the RSA relief in the dust cover. Gen 4 frames (and modified Gen 3), will then have a greater gap when used with Gen 3 slides (although there is no functional loss).

[Mike D]

You'll like the G40, (though the top does not exchange with the G20). You'll find the G40 is the "cat's pajamas" when it comes to working in the field with a semiautomatic pistol. The only thing that could improve the handgun would be a 7" custom Glock barrel with polygonal rifling. this would increase your velocity while making the pistol even more muzzle heavy. This is not altogether negative as it tends to further mitigate recoil, permitting you to quickly return to your target.

Polygonal rifling "squeezes" every bit of velocity from your ammnuition,  increasing range, energy and flattening trajectory.

Enjoy your new Glock. (I'm certain you will).

Why would the G20 to not exchange with the G40? The frames are the same.

Also I've always thought the same thing about polygonal rifling but I chrono'd the exact same loads  from my g42 and my Kahr P380 and the Kahr was faster and I mean quite a bit faster. May have just been a fluke but I checked it twice with the same results.

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[DM1906]

You'll like the G40, (though the top does not exchange with the G20). You'll find the G40 is the "cat's pajamas" when it comes to working in the field with a semiautomatic pistol. The only thing that could improve the handgun would be a 7" custom Glock barrel with polygonal rifling. this would increase your velocity while making the pistol even more muzzle heavy. This is not altogether negative as it tends to further mitigate recoil, permitting you to quickly return to your target.

Polygonal rifling "squeezes" every bit of velocity from your ammnuition,  increasing range, energy and flattening trajectory.

Enjoy your new Glock. (I'm certain you will).

Why would the G20 to not exchange with the G40? The frames are the same.

Also I've always thought the same thing about polygonal rifling but I chrono'd the exact same loads  from my g42 and my Kahr P380 and the Kahr was faster and I mean quite a bit faster. May have just been a fluke but I checked it twice with the same results.

Sent from my iPhone using Tapatalk Pro

I don't know what he meant, either.

The frames are only the same within the same generation. The Gen3 frame will not accept a Gen4 slide, be it a G20 or G40, without modification to the frame. The RSA relief in the dust cover for the Gen4 is larger, to accommodate the larger diameter RSA. A Gen3 slide will work on a Gen4 frame, but there will be a gap at the dust cover end.