I like the gen 4 grip. But if can find a Gen 3 SF ,then get it.
Both will serve you well for many centuries..

 

Gen 4!!

 

A Gen 3 G-20 with frying pan finish is my bedside pistol. It feeds, fires and ejects whatever I put through it and it fits my hands perfectly. It has a steel guide rod and tritium sights installed but is otherwise stock.
I prefer the Gen 3 over the 4. But honestly you can’t go wrong with either.
Glock’s best gun in the best millimeter.

 

I prefer gen 4 but I would be happy with either.

 

gen 3 as you can easily change out the non-captured main spring if needed ( with diff loads )

 

Bingo! It is much easier and cheaper to change recoil spring weights to tune it to your ammo choices, especially if you handload. I would post a picture of my Gen3 G20 with an aluminun scope rail mount and 4x Burris scope with a LW 9 inch barrel and the chest holster I carry it in, but I would burn this thread to the ground with all the comments about how I just created a jam-o-matic, etc, etc etc... Let me assure you it functions fine, and I can install and remove it easily. when out in the mtns. and it adds a whole new dimension of fun shooting this gun. I realize the dust cover flexes under recoil, and it won't win a damn thing at camp perry But it still shoots reasonably accurately at distance and is a LOT of fun! It fits in my Super Redhawk 454 casull shoulder holster and is much more fun to carry. I gotta believe Elmer is smiling from the range in heaven when he sees me carrying it...

 

I’m partial to G3……most of my Glocks are G3, especially the G20. G3xG19 outshoots the G4xG19. This G4 is also persnickety on what it likes to eat, while the G3’s eat it all!

Just my .02.

 

I would get the Gen 4 for the usual improvements over the Gen 3, unless the Gen 3 was a FPF.

I also like the more aggressive texture and the option to add a larger backstrap.

You can change recoil springs as needed, they're not limited to a specific generation.

 

I am kind of weird but I like the Gen 3 triggers better.

 

I have both and prefer the Gen4.

 

I prefer Gen 3 over 4 in general. My gen 3 G20 has the best Glock trigger I've ever used. It is a very nixe shooter.

 

I am looking at adding a 10mm G20.

I love the .40 caliber Glocks that I have and also loving on the gen 4 RSA vs. the gen 3 version of same. It may result in just buying a gen 4 or perhaps even building one from an 80% gen 3 frame I have. I've built 80% before in Glock and 1911 and they have all turned out to function feed and extract great and also have wonderful accuracy.

My use for the G20 will be somewhat limited with the probability of low round count through it annually. It will used more so for adventures in the areas where black bears and some grizzlies live. I would be shooting it enough to become familiar with it but again the annual round count would most likely be under 500 rounds. To build a 1911 in 10mm would take around 3 months for my schedule with all the fitting and polishing and blood donation while a Glock 20 could be put together in about 3-4 hours.

I will be running Underwood 200g through it almost exclusively and my own hot reloads that will produce velocities and pressures very similar to the Underwood rounds. I have other shooters that fill the needs for shooting a lot and I see the 10mm, for me, to be only a consumer of hot rounds.

If I could find a Glock 80% in a gen 4 large frame it would be an easy decision, but I'm not aware of those out there to be found. Most of those 80% are in gen 3.

QUESTION: Considering the intended ammo to be used would there be concerns between selecting a G20 in gen 3 vs, a gen 4 in this situation ???

Opening the nose of the Poly 80 gen 3 design to accept the larger diameter guide rod of the gen 4 is an easy process. I've done 2 of these for the Glock G20 slides. They work fine.

 

Thanks for the interesting info on modifying the slide.

Will the gen4 RSA now operate with the barrel and slide interacting properly? One of the reasons I like the gen4 format is that captivated spring within a spring RSA.