I've been thinking about taking a sip of the cool-aid as I look for a .45ACP pistol to add to my collection at some point in the future. I've stumbled across the G21SF and found it interesting. One of the real big selling points for me is the ambi mag release since I'm a lefty.

 

Any personal experience or thoughts?

I would get a GEN4, instead of the SF, unless I found a good used, SF.   The GEN4 is more versatile with less recoil. 

 

I would like a 30S and some 21 magazines.

I would get a GEN4, instead.  More versatile, slightly less recoil.  I would like a 30S. 

 

Why the less recoil? They change springs with Gen4s?

 

The Gen4 is on my shortlist, too. Being a Glock I'm sure I could find an ambi-release out there somewhere.

The 21 Gen 4 has a double recoil spring with a little less recoil (to most shooters).  It has a more rough texture, which I like.  Some might not like the rough texture as it can be abrasive.  But, I like it, especially with sweaty hands, etc, and I like the finish on the GEN4 more, as it isn't as shiny and more of a matte finish than the earlier Glock.  It has interchangeable backstraps, which I like, too.  The size of the SF is about the same as the GEN4 small grip size.  The GEN4 medium grip is about the same as the standard 21, and the GEN4 large is, well large.   So, you are getting a 21 and 21SF in the mix.  Also, the cutout on the trigger guard is more pronounced on the GEN4 to get a higher grip and a lower bore axis, and if I remember, the mag release button is larger, too. 

 

They are both nice, but I would pay the extra for the GEN4.  If I needed it for duty, or as my SHTF defense gun, I would go with the Glock for a variety of reasons, including the magazines, however, as a secondary gun for other purposes (or backup) if you don't mind the cost of extra magazines, and if  you aren't going to update the sights (stock are better than the Glock), and if you wouldn't mind the cost of upgrading to an APEX duty trigger, you might think about a S&W M&P 45.  If I was buying a non 1911 .45 ACP, that is what I would get.  And, it is ambidextrous for Lefties with awesome ergonomics.  My only (2) beefs are that it has a slightly higher bore axis, and that it needs more texture... and the texture can be remedied.  And, of course the M&P has changeable backstraps and superior ergonomics.  And, did I mention that it is an American rather than Austrian piece of metal and plastic.

Whatever you do, don't get one of those G21SF's that came out a few years ago, before the Gen 4, and had an ambi mag release (not reversible like the Gen 4, but ambi). Those had lots of problems with the mags falling out while shooting. I believe Glock has a no questions asked return policy on those where they'll replace it with a new G21 if you have one of those ambi models.

 

The current Gen 3 G21SF doesn't have a reversible or ambi mag release, only the Gen 4 has the reversible mag release. I'm a lefty too and I actually prefer the mag release on the left side. Unless you have huge hands you'll have to shift your grip to hit it with your thumb.

 

I agree to go for the Gen 4. I like the more aggressive grip texture. With no blackstrap it's the same size as the G21SF.

It's like buying a car. If you walk in and the new model (gen 4) is the same price as the old left over one (SF) get the new one.

 

However if you can get a deal on the SF buy it.

There is a picture reference on another board,(cannot find it right now) comparing a G21SF to a G21G4.  Basically they are equal. No real reason to consider the G21SF. Without the back straps a G21G4 is a G21SF with better grip pattern, three mags, larger mag release that can be reversed, and a better slide spring.  I will look for the reference.  This is the reason went with G4 and not SF.

The G21 SF Ambi release models are problematic. The ambi release is prone to falling apart or getting stuck. The ambi frames are subject to a unofficial recall by Glock.  I had one, Glock replaced the frame for free, no questions asked. My release did fall apart. I since have replaced my 21SF with the G21 Gen 4. I like the Gen 4 much better. Dual RSA aids in recoil. New grip texture feels much nicer.