Extra Capacity for Compact GLOCKS


Most folks that carry a semi automatic handgun and are serious about concealed carry make sure to carry a spare magazine as often as possible.  A spare mag obviously provides additional ammunition should you be forced into reloading the handgun while responding to a violent encounter, but there are other reasons that may be more important for carrying a spare.  The top of the list for carrying a spare mag as far as I’m concerned is providing a solution for dealing with malfunctions.

Regardless as to why you carry a spare mag you should understand that if you carry a compact GLOCK like the GLOCK 19 or a sub-compact model such as the GLOCK 26, you have options when it comes to the spare mag that you carry.  Your options include brands and magazine capacity.

We will talk about the brands in a bit.  First let’s talk about magazine capacity.  The standard capacity of a GLOCK 17 is 17 rounds in the magazine, for a G19, a mag holds 15 rounds, and a 26 mag holds 10 rounds.  What is great about GLOCK handguns is that a 19 can accept both GLOCK 19 mags as well as GLOCK 17 mags.  A 26 can take mags for the 19 and the 17.

There are some great advantages to this versatility. 

GLOCK magazine compatibility can provide extra capacity on reloads.

Whether you are on the range or involved in a self-defense encounter, more ammunition is typically better.  Having higher capacity magazines than you gun typically holds is a great way to increase the capacity of your handgun.  Increasing the capacity of a full-sized GLOCK like a 17 isn’t terribly practical for concealed carry.  Although 21 and 33 round mags exist, they are large, heavy and difficult to conceal.  When it comes to carrying a 17 round magazine compared to a 15 or even a ten rounder, the difference is minimal as far as weight and concealment are concerned.

There are other great advantages as well!

Higher capacity GLOCK magazines can help you keep up with other shooters on the range.

The extra capacity probably won’t ever come into play in a self-defense scenario, but the peace of mind is nice to have.  Where that extra capacity can come into play is when you are training with a compact or sub-compact gun.  During training or practice, you might find yourself running dry before the full size gun guys do.  

In situations where this matters simply stuff you mag pouches with higher capacity mags.  Sure your 19 or 26 will look different with a 17 round mag hanging out of the bottom, but it will perform perfectly and let you keep up with the big guns.

Reloads are easier with compact guns when using higher capacity magazines.

One of the biggest disadvantages of carrying GLOCK 19 or 26 mags for reloads is that they can be difficult to grasp.  Depending on your magazine and magazine pouch combination, you may not have much surface area to grasp when you reach for that spare during a malfunction reload.

The extra length of a full size mag provies for an easy grip.


Placing a longer, higher capacity magazine into your mag pouch can give you the extra length you need to be able to grasp your magazine firmly and securely when it matters most.

When it comes to GLOCK, versatility is one of the first ideas that comes to my mind.  To keep it simple I gave 9mm examples throughout the post, but the versatility of GLOCK mags isn’t limited to 9mm handguns.  You will find the same interchangeability in GLOCK magazines of any caliber within the same caliber.  The versatiliy of Gaston’s handguns doesn’t end with magazine interchangeabity of magazines.  Caliber conversions add to the versitile nature of guns like the G22.

To make it easy for you to find compatible GLOCK magazines simply take a look at this table to see what magazines will work with your handgun.


Caliber Model Standard Mag Cap Optional Higher Cap Mags




 17 round

GLOCK 33 round mag

Magpul PMAG 21 round

ETS 31 round magazine

19  15 round GLOCK 17 magazine – 17 rounds
26  10 round

GLOCK 17 magazine – 17 rounds

GLOCK 19 magazine – 15 rounds


40 S&W




15 round  GLOCK 40 S&W 22 round mag
23  13 round GLOCK 22 magazine – 15 rounds
27  9 round

GLOCK 22 magazine – 15 rounds

GLOCK 23 magazine – 13 rounds

45 ACP



 13 round  none
30  10 round  GLOCK 21 magazine – 13 rounds



 15 round  none
29  10 round GLOCK 20 magazine – 15 rounds
357 SIG 31  15 round

GLOCK 40 S&W 22 round mag

(should function well) 

32  13 round GLOCK 31 magazines – 15 rounds
33  9 round

GLOCK 31 magazines – 15 rounds

GLOCK 32 magazines – 13 rounds


There are plenty of reasons to carry extended spare magazines if you carry a GLOCK that is less than full size.  The additional capacity, the ability to keep up with other shooters on the range and the incresed area to grip the mag in the mag pouch all make sense for most shooters in some situations.  Of course you need to consider your unique situation and determine if carrying a larger capacity reload makes sense for your situation.  the fact remains that most shooters that carry a smaller gun can find some good reasons to own magazines that extend the capacity of their compact or sub-compact GLOCK.

Paul Carlson, owner of Safety Solutions Academy, is a Professional Defensive Shooting Instructor.  He has spent the past decade and a half studying how humans can perform more efficiently in violent confrontations and honing his skills as an instructor both in the classroom and on the range.

Through Safety Solutions Academy, Paul teaches a variety of Critical Defensive Skills courses in more than a dozen states annually.  Courses range from Concealed Carry Classes to Advanced Critical Defensive Handgun Courses and include instruction for the defensive use of handguns, rifles and shotguns.  Safety Solutions Academy regularly hosts other industry leading experts as guest instructors to make sure that SSA’s students have the opportunity for quality instruction across a broad range of Critical Defensive disciplines.