Glock 21 gen 4 review: a Beast of a pistol

Glock 21 Gen 4 Review

Glock 21 Gen 4

Old meets new, as one of the most proven tactical firearms of a generation gets an upgrade (despite the Glock critic's reviews). This is a Glock 21 Gen 4 Review that highlights the reality of one of the best full-sized firearms on the market.

Glock Legacies

Let's talk about the elephant in the room when it comes to Glock. It's distinctive looks and hard to beat durability have framed the discussion about Glocks since their inception.

Aside from the original concerns by gun control advocates that the "plastic frame" would be able to defeat metal detectors and airport security, which was of course false, the looks and durability of the Glock line of pistols are the obvious talking points.

The looks just got a decent upgrade; the durability has never been in question, but to showcase the Glock expectation: you can literally clean your Glock in the dish washing machine and it'll be just fine. You don't need to, and the lead residue is likely to be dangerous in normal settings. But you can if you want to. The Glock will emerge unharmed.

The parts are nearly impermeable to rust. That is: it's very, very hard to get the gun to rust, and when it does, it's mostly surface rust. Normal users will NEVER be able to accomplish the task. The frame is resilient and flexes which not only dampens recoil significantly but helps to give the gun the type of shock absorption that helps it stay strong.

The simplicity of the build is just a singular aspect to the durability claims and the entire gun is only a few seconds to field strip, but torture tests prove the need for fieldstripping is not a frequent need. A thousand rounds through a Glock 21 is nothing. (Exercise awareness and caution when deciding the frequency of servicing guns)

Why so much content on the durability of the Glock? Because the Gen 4 Glock 21 is even more durable than other Glock models. It's made to a heavier duty standard and offers more steel, more polymer and heavier springs. Model to model it offers more durability than most other Glocks. That bodes well against most other brands and models.

What has changed aesthetically?

Glock 21 Gen 4 - dimensions

The grip/frame patterning/texture has changed. From a pressed uneven texture to a nib type pattern. They have gone away from the subtle bump texture and embraced the separated raised nib pattern that is grid-laid.

There is a "Gen 4" stamping towards the front of the slide

The Guide rod has a hole in the end of it, thanks to the beefier guide rod setup (the slide cut for the guide rod is larger too)

The Mag release for the Gen 4 is larger and flatter

The grip angle is slightly changed, and there are interchangeable backstraps (2 in addition to the factory setting)

The magazines are slightly different, in that they are notched on both sides for the magazine catch. Glock will only be producing Generation 4+ mags after the release date of the Generation 4 magazines.

The following parts are NOT interchangeable from Generation 3 to Generation 4:

Trigger bars

Trigger Housings

Mag Catches

Recoil Guide rod assemblies

Gen 4 has two springs that work in tandem. The Generation 3 has a single spring. You can find adapters to fit a Gen 3 rod into a Gen 4 gun, but since Glock has worked out issues with the newer design, there is no need.

Additionally, many of the aftermarket parts that are still available will not fit. Namely: magazine modifications at the mag well area may not work because of the additional grip backstraps.

How does the Generational change affect the Glock 21?

Up until now we have talked mostly about the changes that come from the whole portfolio generational changes. Now let's talk about how the changes from G3 to G4 have affected the Glock 21.

The only changes are positive. That's the final word on it. (Except, it's not going to be, even if it should be.) In the end you will likely agree that the changes were beneficial, even if on the surface you don’t agree. The point remains though: the value of the changes enhances the ability for the average mainstream user

The grip texture is better for sweaty hands; adrenaline filled moments and gloved hand shooting. Period. Most users that care about the grip are going to custom modify the grip for more aggressive texture anyway, and this eliminates the need to do that through some deep stippling or other modification.

This is a huge advantage for most shooters who already felt that the subtle bump texturing was lacking in grip promoting anatomy.

It is this grip improvement that marks the largest aesthetic and functional change for the gun, as most of the others were not "problems" before the "upgrade".

Glock 21 Gen 4 - 2

The recoil spring is a beneficial improvement if only for the less frequent need to change springs for high volume shooters, but more than that, the help in overall functionality that is gained from a dual spring and a larger diameter rod underlaying those springs means that the punishing round that the G21 shoots is tamed significantly from a frame and barrel lockup perspective.

The Glock 21 was already a fairly mildly recoiling pistol considering the .45ACP round it fires; and the recoil rod improvement was made for functional purposes, not recoil dampening.

This larger diameter rod and dual spring makes for a substantially stronger piece and does away with the famous "flat spring" once and for all. Captured, this is a guide rod that doesn't need to be wrestled into the gun, it just works.

A note: at first the new design for the guide rod simply did not work. It fell out and separated and caused reliability issues. Glock responded proportionately to retain their reliability reputation. The problem was resolved nationwide in about a month.

Contemporaneously; looking back, this guide rod fix has held up superbly since then (some 20+ or so years since the "original" Gen 2, American market model; and now, itself 10 years in production).

The grip and the guide rod help functionality immensely for the .45 Auto pistols, including the Glock 21. This is a 13 round pistol that is made in a full-sized format. It is the original, and still flagship .45 auto in the Glock lineup.

The improvements from Generation 3 are also prevalent on this model including the finger grooves and the accessory rail. These can have a huge impact on handling such a large pistol. Especially for those who don't mind weight but need balance and recoil control.

Make no mistake, though, the Glock 21 is a beast of a pistol and those with stubby fingers will find it hard to control masterfully; those with small hands will find it even worse. The grip frame is significant, and the Gen 4 improvements can slim down the backstrap and help out a lot.

More than anything, the Gen 4 backstrap can improve first time Glock shooter's impression of the gun and make it a true pointing firearm without the learning curve that comes with the famous "Glock Bump".

What are the main points of the Glock 21 Gen 4?

There are two models available from Glock factory: the Glock Gen 4 21 and the Glock Gen 4 21C. (a Generation 3 equivalent is also still available in the format of the SF – Short Frame)

The two GEN 4 models are EXACTLY the same in every dimension, with the following exceptions:

The Glock 21C is 29.10oz. empty, and the Glock 21 is 29.28oz. empty. This is because of the two cuts in the barrel and slide towards the front to serve as a compensator, to mitigate some of the recoil and muzzle rise of the .45 Auto pistol.

The G21C is vastly less popular than the G21 in any format but is a very nice firearm for all uses that the G21 is appropriate for, except that of low light shooting.

Alternatively, the Gen3 Glock 21SF has the same weight as the Compensated model (29.10oz empty with magazine).

It's important to know that the grip size is the same (with no backstrap) on the Gen4 G21 and the Short frame (minimized frame) G21 of the 3rd Gen Glock.

That makes the choice between firearms very similar and means that anyone who doesn't explicitly prefer the Generation three buildout of the Glock 21, might be a perfect candidate for purchase of the Gen 4 firearm.

The gun features 13 rounds of .45 ACP ammunition. It offers a full-sized frame and it is not for the smaller concealed carrier.

It is easily controlled by most shooters, even those with hands on the smaller size, or those that have an aversion to excessive recoil and muzzle flip. The .45 ACP round in a polymer full-sized firearm is not as difficult to handle as it is in other pistols.

The magazine, and the entire system built by Glock is exceptionally reliable and durable. There are many guns that have more than 50,000 rounds through them. Most shooters, thanks to the relatively inexpensive cartridge can shoot many thousands of rounds of all types of .45 Auto through their G21's. 

It is among the most proven Glock pistols in the model range. It is also one of the most beloved, especially amongst new school shooters who grew up in the generation of the polymer framed semi-automatic pistol that Law Enforcement moved swiftly into, and kept as their sidearm for now, decades.

Glock 21 Gen 4 Review: Conclusion

If you want a new full-sized Glock Firearm in .45 there is not another choice that makes sense currently other than the Glock 21 Gen 4. The ability to easy modify the firearm; it's inherent reliability and the obvious stature of the firearm in the annals of modern pistols means you are getting nothing short of a top tier pistol in the famous .45 ACP caliber.

Watch a Glock 21 Gen 4 review from hickok45

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