Glock 21 Review: Should this Glock replace your 1911?

by Daniel Young

May 20, 2024



As a lifelong gun nerd, I’ve had my fair share of experiences with different firearms. But let me tell you, the Glock Model 21 is something special. Introduced back in 1990, it’s managed to bring the classic .45 ACP caliber into the modern world of handguns. So, in this review of the Glock 21, let’s take a closer look at why it’s become such a popular choice among shooters today.

So, I reviewed this gun last year. But recently, after using it more and firing lots of rounds, my thoughts on this gun have changed a bit. Keep reading this review to see what’s different now

A full size Glock handgun chambered in 45 ACP, ready for duty.

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Glock 21 Specs

  • Name Glock 21
  • Caliber 45 ACP
  • Capacity 13+1
  • Action Striker Fired
  • Frame Polymer
  • Sights Polymer
  • Barrel Length 4.61 inches
  • Weight Loaded 38.8 ounces
  • Safety None

Glock 21 Background

Glock’s first models were chambered in 9mm, followed by 10mm. The G21 introduced the ubiquitous .45 ACP chambering to Glock’s lineup in 1990. Much like their other models, it features a polymer frame with a steel slide.

While it may seem outdated today, in the 1980s and 1990s there were real concerns about the lethality of the 9mm Parabellum cartridge. The infamous FBI shootout in Miami in 1986 resulted in the deaths of several agents, and the failings of the 9mm ammunition available at the time directly contributed to the bad outcomes of that engagement. The post-incident reviews ignited a search for more effective handgun calibers and ammunition. 

The .45 ACP was able to meet the standards laid out in the new regime of ballistics testing. It also had a reputation for effectiveness stemming from two world wars, Korea, and Vietnam. And the most prevalent .45 was the 1911.

The G21 was created for shooters who wanted a .45, but wanted a lighter, more reliable, higher capacity pistol than the 1911. The 13-round magazine is almost double the capacity of a 1911. A loaded G21 weighs about the same as an empty 1911. 

More recent advances in ammunition technology have obviated the advantages the .45 ACP once held. 9mm has become the default choice for defensive handguns. But the venerable .45 still has certain advantages, particularly when suppressed, and it remains a key player in the Glock lineup.

Glock 21 Features

Glock 21 Features
1 High capacity for a .45 ACP

At 13 rounds, the Glock 21 magazine is almost double that of a standard 1911!

2 Legendary Glock reliability

Glocks are known as reliable firearms, and the Glock 21 is no exception.

3 Light weight for its category

When compared to metal framed 1911s, the Glock 21 is much lighter to carry all day on duty.

Models and Variations of the Glock 21

This review is specific to the G21 Generation 3 Short Frame, but is very comparable to the newer Generation 4 model. Older Gen 3 models had even larger grips, but the SF and Gen 4 models have improved this slightly. The Glock 41 is a related model, with the frame of a Gen 4 G21 and a slimmed down extended slide.

Glock 21 –  Our Take

Glock 21 Patch

A heavier caliber gun will always produce more recoil than a lighter caliber. The laws of physics are laws. Accordingly, the G21 has more recoil than a compatible 9mm model like the G17. It is not, however, a difficult gun to shoot. The Glock 20 is the same gun, but chambered in 10mm. They perform similarly, but the muzzle flip is more pronounced on the .45 Auto. This is due to the additional mass of the larger bullet. Neither is abusive or painful in any way, but recoil control takes more effort than smaller calibers. 

Reduced capacity and increased recoil are obvious disadvantages to the .45 ACP generally, and those remain true on the G21 as well. The added recoil over a 9mm slows down the rate at which aimed shots can be taken. Yes, with training and practice, it can still be fast enough. But it will be more difficult, again, because the physics are what they are.

As for the decreased capacity, that is a factor too. But it is not as much of a factor in the specific case of a G21. Going from a 7-round 1911 magazine to a 17-round G17 magazine is a real difference. But comparing that same G17 to the 13-round magazine in a G21 is not as wide of a gulf. It is also a fair argument that in most civilian defensive shootings the 4-round difference between the two is very unlikely to be an issue. If you personally prefer shooting a .45, the Glock 21 emerges as one of the most sensible options out there.

Glock 21


Ergonomically, the G21 is like any other Glock but a little “chunkier.” The grip diameter is noticeably larger than the 9mm or .40 S&W models. Recent variants like the Gen 3 Short Frame and Gen 4 did reduce the grip size, but it can still be an issue for shooters with smaller hands. 

The slide of the G21 is substantially larger than the slides found on the 9mm or .40 S&W Glocks. This causes the gun to feel top heavy when unloaded. However, when loaded, this is balanced out by the weight of 13 rounds of .45 ACP in the magazine.


Glocks are boringly reliable. That is exactly what you want in a defensive handgun. The G21, while it may lack the charm of other guns, compensates with its extremely reliable performance. This is not a gun that must be perfectly cleaned and lubricated to function properly. It is probably the most reliable .45 ACP on the market.

There is little to say about the controls of the G21. They are the same as any other Glock. As of the time of writing, there is no Gen 5 model 21, so ambidextrous slide catch levers are not available. The trigger safety, magazine release button, and slide catch work as would be expected and are located in the normal positions. Disassembly is also the same as the rest of the family.

One of my few gripes with the Glock 21 is the use of cheap plastic sights. Aftermarket metal sights need to be added for any serious use, and night sights would be even better. Plan on budgeting for better sights if you pick up a G21.


The Glock 21 boasts solid accuracy. It is not the equal of something like a match grade 1911, but it will still outperform most end users. Even with the subpar factory sights, it will still shoot solid groups. The striker fired trigger mechanism is not a light, crisp single action pull, but it is still very usable. 

Aftermarket support is decent, but not exceptional. There are a decent variety of holsters available including duty-grade models (because the G21 has been issued to police forces around the U.S.). Spare magazines are readily available, and the integrated accessory rail facilitates the mounting of weaponlights or lasers. Do not expect a large range of compensators and niche accessories as can be found for the G19.

Glock 21 Pros and Cons 

  • Capacity – Good capacity for a .45 ACP
  • Reliability– Excellent reliability
  • Size – Large grip
  • Top Heavy– Top heavy handling

Report Card


Muzzle flip is pronounced but it is still a solid shooter


It just plain works, rain or shine


Girthy grip may be an issue for some, but it’s not a deal breaker


The stock trigger is not match grade, but it still shoots solid groups


Street price around $550 is fair, even considering the sights

Glock 21 Review Final Grade

Our Grade


Reviewed by Daniel Young

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Based on 11 Reviews

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If you are looking for a Glock 21 we’ve done the legwork for you. Here are some of the best deals you’ll find when searching for your new Glock 21.

Glock 21 – FAQs

Is the Glock 21 suitable for duty use or concealed carry?

If you’re considering the Glock 21 for duty use, its reliability and high capacity make it a solid choice for law enforcement or armed professionals. However, if you’re thinking about concealed carry, its larger size and weight might not be the most comfortable option, particularly if you have a smaller frame or prefer more compact handguns.

How does the Glock trigger feel compared to other handguns?

The Glock 21’s trigger is known for its consistent pull and relatively short reset. While it’s not as light as some match-grade triggers, it offers reliability and predictability for most shooters.

Are the factory sights on the Glock 21 good for accuracy?

The Glock 21 comes with polymer sights as standard, which you might find lacking in clarity. However, upgrading to aftermarket metal sights can significantly enhance sight picture clarity and durability, improving overall accuracy for you.

Does the Glock 21 have a comfortable grip angle?

As for grip angle, the Glock 21 maintains a comfortable angle of around 22 degrees, promoting natural aiming and pointing that you might find intuitive and comfortable.

Glock 21 Starter Pack

If you’re serious about owning a Glock, there are a few extra things you’ll probably want to pick up–if you don’t have them of course.

  • Sights: Do factory Glock sights work, yes. Should your replace them as soon as you can, yes. Check out our review of our favorite Glock sights
  • Magazines: Having extra magazines is a must for any gun that you own–unless you like wasting time excess time reloading. Pick up some factory Glock 21 mags over at Palmetto State Armory
  • Gun Cleaning Kit: You need to maintain your firearm to keep it reliable. We’ve got a whole article dedicated to gun cleaning kits you’ll need to keep your pistol in tip top shape.  
  • Eye Protection: This should go without saying, but you need to invest in some quality shooting glasses. One errant piece of brass, and you’re in for a bad day. Check out our recommendations for the best shooting glasses!
  • Hearing Protection: Protect your ears and get some quality hearing protection. We’ve gathered all of our favorites to help you decide the best hearing protection for you.

Upgrades and Accessories for the Glock 21

Glocks may have the largest aftermarket support in the industry. Check out our some upgrades we think you will like below:

Best Accessories For The Glock 21

AccessoryDetailsCheck Price
Trijicon HD Nights Sights
Trijicon HD Night Sights
  • Rugged Design
  • Day and Night Sight
Check Price
Glock 21 Magazine
Factory Glock 21 Magazines
  • 13 Round Capacity
  • 45 ACP Double Stack
  • Polymer
Check Price
Ghost Minus Connector Glock
Ghost Minus Trigger Connector for Glock
  • Drop in replacement
  • 3.5 lb trigger pull
  • smoother, lighter and more consistent trigger
Check Price

Best Ammo for Your Glock 21

We recommend that that for every firearm you own to procure two different types of ammo–one for training and one for working. For the Glock 21, you’ll want some ball ammo to practice at the shooting range with and some high quality duty ammunition to really make the most out of your purchase. 

Range Rounds

Magtech 45 ACP

MagTech 45ACP 230 GR FMJ

Cost Per Round
Natchez Shooter’s Supply $0.49
Palmetto State Armory $0.52
Brownells $0.58

Duty Ammunition

Federal HST 45 ACP Ammo

Federal Premium 45 ACP 230 GR HST

Cost Per Round
Natchez Shooter’s Supply $1.67
Palmetto State Armory $1.69
Brownells $1.67

Other Pistols of its Class to Check Out

The Glock 21 is a good option for duty. But if you’re not sold on Glock or 45 ACP, there are other options out there. See below for some of our favorites. If you like the 45 ACP and want to stick with the 1911 aesthetics, check out our Best 1911 review. 

#1 Glock 17 Gen 5 MOS : Duty Glock in 9MM

Glock 17 Gen 5 MOS

Glock 17 Gen 5 MOS

Revolutionizing the world since the late ’80s, Glock is a defacto standard across the world for civilians, military, and police.

Check Latest Price

  • Shootability A
  • Reliability A+
  • Ergonomics B+
  • Accuracy A
  • Value A

Our Grade


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Based on 12 Reviews

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The Glock 17 is a gold standard in full size duty handguns. If you like Glocks, but want to more capacity this would be a great options.

#2 Remington 1911 R1 : Classic 1911

Remington 1911 R1

A dominant force in competition. For sure handling, the flat mainspring housing and beavertail grip safety are checkered 20 LPI. Also features a robust fiber-optic front sight, extended performance trigger adjustable for overtravel, adjustable rear sight and two 8-round magazines.

Check Latest Price

  • Shootability B+
  • Reliability B
  • Ergonomics A-
  • Accuracy B
  • Value B-

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Based on 10 Reviews

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#3 Springfield Prodigy Full-size 5 Inch : Modern 1911

Prodigy 1911 DS 5 inch

Springfield Prodigy Full-size 5 Inch

The Springfield Prodigy is an excellent double-stack 9mm 1911 with many performance upgrades straight from the factory.

Check Latest Price

  • Shootability A+
  • Reliability A+
  • Ergonomics A+
  • Accuracy A+
  • Value A

Our Grade


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Based on 5 Reviews

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How to Care for Your Glock 21

Caring for your Glock 21 is the same as any other Glock. Check out this video to get a thorough walkthrough.

Looking for some more information on the Glock 21? Check out the links below for the manufacturer’s website, operator’s manual, and other neat content.


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About Daniel Young

Daniel is an attorney and lifelong gun nerd. His Instagram account, @fromtheguncounter, grew out of his work at a gun store and shooting range. He can usually be found in the hills with a rifle when he's not working.

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  1. After several thousand rounds on range as a LEO, I traded down to a .40 from the Glock 21. It is too too heavy and the grip is too big. I have large hands and it shouldn’t have been much trouble but I found it difficult under speed drills with induced stress. I would not endorse the model for most recreational buyers

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