Glock 21 Vs Glock 21SF : Are These Two Guns Similar with Just Different Frame?

You might know Glock 21SF from the movie “John Wick: Chapter 3 – Parabellum”. Glock 21 has been in fame since “Die Hard 4.0” and “The Expendables 2”. Both share similarities, one of them being the reliability of the good old Glock.

However, the two guns are also different from each other. This includes their caliber, capacity, and overall design.

This article will provide a comprehensive comparison of the Glock 21 Vs Glock 21SF. So stay tuned till the end to find out.

Glock 21 Vs Glock 21SF

Glock 21 Vs Glock 21SF: A Complete Differences

Quick Comparison Chart

FeaturesGlock 21Glock 21SF
Cartridge.45 ACP.45 ACP
SightFixed polymer sightsAdjustable polymer sights
Magazine13 rounds13 rounds
Weight29.28 oz. (unloaded)29.10 oz. (unloaded)
Length8.22 in.8.03 in.
Barrel length4.61 in.4.61 in.
Width1.27 in.1.27 in.
SafetyTrigger, Firing PinTrigger, Firing Pin
Height5.47 in.5.47 in.
Gun TypeSemi-Automatic PistolSemi-Automatic Pistol
DesignPolymer framePolymer frame

Taking a look at the above box, it is easy to see that there are very few tangible differences between the two. They are more similar than they are different.

The features of the Glock 21 and Glock 21SF are discussed below:

Related Post: Glock 21 Vs. 19 –

1. Ammo:

Both the Glock 21 and Glock 21SF perform well with various brands of hollow-point ammunition. This includes Federal HST 230, Hornady Critical Duty, and Speer Gold Dot.

Ammunition such as the 185-grain +P loads from Federal and Remington Golden Saber 185 grain rounds give better results with the Glock 21.

It is to be noted that both the Glocks give a 100% reliable performance with these ammunition.

2. Recoil:

The recoil spring assembly in both models is the same. It helps to reduce felt recoil and muzzle rise.

The Glock 21 originally came with a 17-pound recoil spring assembly. This spring is known to be quite stiff, making it difficult to manipulate for some shooters. Especially for those with smaller stature or weaker hands.

On the other hand, the recoil spring on the Glock 21SF is 16 pounds. The heavier spring supposedly makes the gun easier to use and reduces felt recoil.

Moroever, due to its smaller grip size, users claim that the Glock 21SF has less felt recoil than the standard Glock 21. Other users have stated that the Glock 21 has a ‘sharper’ recoil.

The recoil is felt differently by different users.

3. Sights:

The Glock 21 has fixed sights, which are also known as “combat” or “standard” sights. These are simple and dependable, and they perform admirably in most shooting scenarios.

However, they might be difficult to use in low-light conditions or at longer ranges.

On the contrary, Glock 21SF has adjustable sights for greater customization and precision. Furthermore, they are more comfortable and easier to use overall.

Moreover, plastic sights that come with the Glocks do get the job done. But they are not by any means exceeding expectations.

4. Magazine:


The magazines of the Glock 21 and 21SF are not interchangeable. The reason is the changes inside the internal changes done to the 21 vs 21SF as shown in the picture.

So the magazine with a plate at the back fits the Glock 21SF.

On the old Glock 21, the Glock 21SF magazines can be used.

Here’s the catch:

Gen 4 Glock 21 magazines will work in any generation 21 or 21SF.

Gen 3 Glock 21 magazines will work in 1-3 generations of Glock 21 or 21SF.

Gen 3 Glock 21 magazines will work in the gen 4 Glock 21. But only if you keep the magazine release on the left side of the frame.

5. Grip Texture:

The 21 Gen 4 without the backstrap is described as having the same grip as the 21SF. I found the 21SF grip to be more comfortable.

It may just be “feel” but if you compare the grip size from the back, the SF has a smaller one. There is about 1/8th of an inch of difference.

This may be what makes it more comfortable.

6. Aesthetics:

Occasionally, you may see a Glock 21SF with Picatinny rail, and ambidextrous magazine release buttons. These were made for a short time as a short-frame option.

On the other hand, the Glock 21 has a Glock accessory rail. Which is not present on the 21SF.

7. Pull Length:

The pull length is the distance between the back of the back strap and the trigger. This distance is greater on the 21 than it is on the 21SF.

The distance from the back of the back strap to the trigger is shorter on the Glock 21SF

That has the effect of making it feel like the 21 is kind of bulky. So people with small but chubbier hands feel like they are using a fat gun.

8. Accuracy:

The Glock 21 produces 1.5″ or a bit less for 5 shots at 25 yards (Watch Masood Ayub’s video if you haven’t already!). Jeff Quinn of shot a 1-3/8″

With the Glock 21SF, consistent 3′′ shots can be produced from 5-round groups. It can be shot with Hornady’s Critical Defense 185gr FTX or Winchester white box 230gr FMJ at 25 yards. Even the Remington Ultimate Defense 230gr JHP round delivers 2-round 3/4′′ groups.

9. Range:

The Glock 21 is the most accurate around 25 yards. Whereas the Glock 21SF can do 50 yards maximum.

Overall, it seems that both the Glock 21 and Glock 21SF are capable of accurate shooting at longer ranges. But the 21SF gives better range.

10. Safety:

Both the Glock 21 and 21SF feature three internal safeties. These are simultaneously deactivated and reactivated when the trigger is pulled.

However, there is no safety to prevent you from accidentally pulling the trigger.

Which Generation of Glock 21 Is the Best?

The Glock 21s can be older or newer and the latest is Gen 4. The original Glock 21 featured a non-textured grip and no accessory rail. It also had a slightly different slide design than later generations.

The second generation of Glock 21 introduced a textured grip. Glock also added the accessory rail on the frame. Moreover, a new recoil spring assembly was also incorporated.

The third generation of Glock 21 introduced finger grooves on the grip and an enlarged magazine release button. The slide was also redesigned with a new extractor and ejector.

The Glock 21 fourth generation introduced a modular backstrap system. It allowed the shooter to customize the grip size. It also had a new dual recoil spring system and an improved recoil spring assembly.

Although each generation has its attractions, most tend to go with the gen 4 ones. However, for some, the gen 3 fits their hand the best. It really depends on the comfort of the users.

Which Generation of Glock 21SF Is the Best?

The Glock 21SF was introduced in 2007 as an update to the original Glock 21. It features a reduced grip size (Thus the term SF; short-frame). As of April 2023, the Glock 21SF is only available in the third generation.

Many Glock enthusiasts prefer the third-generation of Glock 21SF models in general. This is due to their reputation for reliability, simplicity, and performance. It also includes compatibility with a wide range of aftermarket parts and accessories.

Cost Details Between Glock 21 Vs Glock 21SF

The cost of new Glock 21 guns cost around $586.99-$599.99. Whereas the used ones cost $546.99-$560.99.

The Glock 21SF pistol is currently worth an average price of $467.45 to $488 new and $425.73 to $437 used.

So the Glock 21 easily is pricier than the Glock 21SF.

Glock 21 Vs Glock 21SF – FAQs

Can you interchange parts between the Glock 21 and Glock 21SF?

Yes, many of the parts between the Glock 21 and Glock 21SF are interchangeable, including magazines, slide assemblies, and recoil springs.

Which is better for concealed carry, the Glock 21 or Glock 21SF?

Neither the Glock 21 nor the Glock 21SF is particularly well-suited for concealed carry due to their large size and weight. However, the Glock 21SF may be slightly more manageable for some due to its smaller grip frame.

Can I use Glock 21 accessories with Glock 21SF?

Holsters, sights, and lights can be interchanged between Glock 21 and 21SF. However, backstraps and grips may not be compatible.

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