Since the introduction of the Glock semi-automatic handgun. Glock has been the choice for so many shooters including many Law Enforcement agencies, primarily, the FBI. With it’s striker fired functionality, its not only easy to shoot a Glock, it is safe and effective. The FBI carries a modified Glock 19 which fires a 9mm. We are going to do an overview of it’s larger caliber brother – the Glock 21.

Glock – Plastic Perfection

We have a Glock 21 here with us today on the range we are seeing how well we shoot with it. The Glock 21 is chambered in .45 ACP pistol that has a standard magazine capacity of 13 rounds. It is a striker fired weapon so the hammer is internally located under the slide. No need to manually cock the hammer back for this pistol.

Quick History

The Glock pistol was introduced in the early 1980. The Glock 17 was the first version to be put into service by the Austrian military. Since then, there have been many different models that shoot at different calibers and at various sizes. There have also been a number of “generational” model changes and improvements throughout the years.

Firearm Overview

Glock has used the term “Plastic Perfection” as their motto. This is because their gun frames are made of a tough plastic polymer that is not only reliable but it very lightweight verses the more metal based frame of most other handguns. Lets see how this all works.

Check out the images below for reference:

Glock Breakdown

Colt M1911 Breakdown
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Barrel behind Slide

The long cylinder where the round is shot out of. It is underneath the slide which is used to help cycle a new round

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Magazine/Magazine Well

The part of the handgun that locks the magazine in position for feeding cartridges into the chamber of the firearm

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Front and Rear Sights

Reticle device for aiming the weapon. Standard iron sights are pictured here with front sight and rear sights.

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Activates the firing pin which fires the round.

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Magazine Release

(Under Thumb) Button that releases the magazine so it can be changed out

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Reinforced Grip

Handle to wrap your hand to aim. Reinforced with textured gripping

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Slide Catch and Release

Lever that catches the slide on empty. Use lever to release.

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Ejection Port

The port where the used empty shell ejects from after fired

Once you have a good idea of where these important gun components are located on the weapon, you should know what is referred to in this “how-to” article.

Loading the Magazine

Glock Load Magazine

There are a number of things great about Glocks but one of my favorite is loading the magazine. Glock magazines are super easy to load. Whether it’s .45 ACP for the Glock 21 or any other caliber for the other Glocks, loading Glock magazines are great. 

Start by grabbing an empty magazine in the off hand (not the hand you are going to shoot with) and use the fingers of your precision hand to get a round. Hold the magazine well in your off hand and align the round with the top of the magazine. Make sure it is facing the correct way to the front of the magazine and push it down so it is pushed underneath the lips of the magazine. At round 9 or 10 is where it will get more difficult to insert a new round into the magazine. Since Glock magazines are pretty wide and the lips are not narrow, it shouldn’t be too bad. Keep adding a round to the magazine until you cannot add anymore. The top is 13 rounds.

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Load the Glock

Glock Load Gun

Insert the magazine

Once you are done loading the magazine, it is time to load the Glock with it. The magazine will go into the open magazine well at the bottom of the grip. Use your off hand to pick up your loaded magazine and pick up the Glock by the grip in the other hand. Make sure the magazine is front facing with the bullets pointed away from you. Line up the magazine with the open magazine well on the pistol. Push the magazine all the way up into the magazine well until it cannot go any further. Give the bottom of the magazine a good tap up to make sure the magazine is seated well inside. The gun will not cycle if the magazine is not seated correctly so be aware of that.

Loading a round

The slide the long piece that covers the barrel on top. The slide also has an opening for the ejecting shell brass of the bullets once they have been shot. This slide needs to be pulled back all the way so the gun mechanism can load a round from the magazine to the chamber of the Glock. Use your off hand to grab the back of the slide and pull it straight back. You should be able to see a round from the magazine inside the ejection port. Once you cannot pull it back any further, let it go and this will load a round into the chamber for firing. The Glock is now ready to shoot.

Warning: You now have a loaded pistol. Make sure your finger is off the trigger until ready to shoot.

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Firing the Glock

Colt M1911 Fire Gun

Ready to Fire

Glocks don’t have a manual safety so you don’t have anything to press or flip before shooting. Glocks have passive safeties to ensure that they don’t go discharge prematurely. Some shooters like this feature and some shooters do not. It makes things easier for self defense by not having to add an extra step when time is of the essence. But, a manual safety could be useful if a child or unqualified shooter got their hands on it. It is purely a shooter’s preference. 

A Glock is also a striker fired semi-automatic pistol so cocking a hammer is also not needed since the hammer is located under the slide. Once you pull back the slide to chamber a round, you are good to go to fire. You don’t have to worry about anything else.

Warning: You now have a loaded pistol ready to fire

Lining up your shot

To shoot your Glock, use any stance you feel you are comfortable with to line up your shot at a target. With two hands now on the pistol grip and your arms extended out in front of you, raise your pistol so you can fire. Use the pistol sights so you can line up your target accurately. You will want to put the front sight dot in between the back sights to aim properly. Use the picture for reference. Once you are lined up correctly with your target. Pull the trigger to fire. Firing .45 ACP rounds can cause quite a bit of recoil , especially for newer shooters so make sure you have a firm grip on your Glock. Keep firing until satisfied or empty.

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Reload the Glock

Reload Colt M1911

Magazine Trade up

The Glock 21 has a good amount of ammo the magazine for a .45 ACP caliber handgun so you wont have to reload as often as much. Eventually you will manage to empty your magazine and you will want to reload. Now is the time to reload with a spare loaded magazine. If you do not have a spare loaded magazine, go back and repeat the Load Magazine section to repeat the process of loading the magazine you have with new ammo. If you do have a spare loaded magazine, it is time to remove the empty one and rplace it with the new one.

With your thumb or a finger on your other hand, hit the square textured magazine release button that is located right below the trigger. When you hit it, make sure you have your other hand catch it because it is likely to fall out. You can also guide it out with your hand. Put the empty magazine away or to the side and grab the new fully loaded magazine with the same hand. Make sure thing are lined up correctly with the ammo facing away from you. Put the magazine up in the magazine well of the Glock as you did once before and give it a tap to ensure that it is seated properly.

Hit Magazine Release and pull out magazine
Prepare fully loaded magazine
Hit Magazine Release and pull out magazine
Prepare fully loaded magazine
Insert new loaded magazine
Hit bolt release to chamber new round
Insert new loaded magazine
Pull slide back or hit slide release

Release Slide Lock

As you may notice, the slide is in the back position. The slide catches once you are out of ammo. Once you have a new magazine loaded in the pistol, releasing the slide with chamber a new round. With your thumb, you can hit the small slide release on the side of the pistol right above the trigger. Releasing the slide will chamber a round and now you are loaded to fire again.

Warning: You once again have a loaded pistol

Now you are good to go. Reassess your target to be fired upon once again. Repeat the Firing section to continue firing.

Clearing the weapon

If you are completely done firing, remove the magazine as you would when reloading. Instead of putting a new magazine in, put it away or to the side. Pull back the slide to see if there is a round in the chamber still. If there was, pulling back hard on the slide would have most likely ejected the round for you. The weapon should now be clear of any ammo.


The Glock 21 is a very dependable .45 ACP caliber handgun. A semi-auto handgun with high stopping power and the reliability of a Glock. You really can’t go wrong. This gun is also featured in Call of Duty: Modern Warfare as the X16. Take a look at that if you are interested.

All in all, get better by learning as we are. To do this you have to practice. Practice Makes Proficient.