View Full Version : G20 or G21? (or 10mm vs 45Acp)

Old Sarge
March 15, 2015, 12:08
Hi All
So I have been kicking this around for a couple of days now. I am thinking of picking up one of the full sized SF Glocks and am torn between the G20 and the G21. I have shot a 1911 for years so I have lots of ammo, brass and reloading gear. 10mm would be new for me. I have some brass (no where near what I don in 45Acp) no ammo, and I have the reloading gear as its the same as the 40S&W's.

So is the 10mm going to give me anything over the 45Acp? Or would I just be getting into a new caliber?

Old Sarge

March 15, 2015, 12:46
If I were in your shoes I'd go with the 21. You already have lots of ammo/components for .45ACP, it's easier to find and cheaper to shoot. Plus the majority of the factory 10mm around is loaded down compared to the original/red-hot 10mm load. Realistically contemporary 10mm isn't going to do much that new mfg/SD .45 will do (I'm talking average factory loads, not boutique stuff).

I've had my G-21 for over 10 years and I've had a few thousand rounds thru it and it's been 100%- one or my favorite Glocks.

March 15, 2015, 13:23
Plus if you want the hot stuff you can get some 45 super brass and appropriate recoil spring.

March 15, 2015, 15:31
I have both the G20SF, and G29SF, both 10mm. I think the 10mm is the ideal caliber for semi-auto, provided that you use full power loads. I use only Underwood ammo, ( besides my recent run-in with my friend using his hand load in my gun and blowing it up) which is excellent quality, accurate, and very hot. You will need a heavier weight spring when using Underwood ammo. I use a 22lb in the G20, and it can handle any of the Underwood loads. If using regular factory 10mm, you will be disappointed, and won't really see any real difference between the .45.


March 17, 2015, 12:19
I think hot loaded 45.'s are very close to 10mm and probably easier to shoot, the 10mm kicks like a bitch, not for wimps.

I'm looking at a G20 right now, the guy needs money really bad, I think he'll let it go for around $300. my Glock collection is getin big. :cool:

700 Foot Lbs of energy......OUCH :uhoh:


Technical Information •Caliber: 10mm Auto
•Bullet Weight: 140 Grains
•Bullet Style: Lehigh Defense CF
•Case Type: Brass

Ballistics Information:

•Muzzle Velocity: 1500 fps
•Muzzle Energy: 700 ft. lbs.

March 17, 2015, 12:24
This puppy won't buff out..... 2238 fps out of revolver, insane.

•Caliber: 500 S&W Magnum
•Bullet Weight: 700 Grains
•Bullet Style: Lead Flat Nose Gas Check 21 BHN

•Case Type: Brass

Ballistics Information:

•Muzzle Velocity: 1200 fps
•Muzzle Energy: 2238 ft. lbs.