Glock 45 and Sig M17 Handguns: A Comparison Review

— Jason MosherCADRE Dispatch

Glock and Sig Sauer are legendary gun makers and both have earned a worthy reputation. In this article, we will be comparing the 9mm Glock 45 and Sig M17. I’m not going to get into which one outshoots or outlasts the other because there’s no point. Quality and reliability have been tested extensively and both are among the best of the best.

Instead, we are going to look at the differences in each gun, including accessories and holsters available. We all have different tastes in guns and must select the option that fits our needs most.

Glock 45 and Sig M17.
The Glock 45 and Sig M17 are both reliable and used by many around the world. [Photo: Jason Mosher]

Henry Ford once said, “Any customer can have a car painted any color that he wants so long as it is black.” Gaston Glock often reminds me of Henry Ford. He found something that worked and stuck with it.

Just about every Glock looks and functions the same. While Glock does produce four other colors of handguns besides black, most of them are going to be the standard black pistol we are used to seeing. The choices Glock provides are caliber and frame size.

Sig Sauer on the other hand produces many handguns, sub-guns, and rifles. They also make optics, lights, and other accessories for guns. One of their more popular guns, the Sig P320 was chosen by the US Military as the standard issue sidearm. Designated as the M17, it has become a popular choice in the civilian market.

I’ll go over each one and then take them to the range for some comparisons. Let’s start with the Glock 45.

Glock 45

The late Gaston Glock chose to number his firearms in the order the design was started. This can be confusing because people often think a G45 is a .45 caliber gun. Or that a Glock 22 is a .22 rimfire handgun. Neither of these two assumptions would be correct, however.

A Glock 45, which we are looking at today, is a 9mm, striker-fired handgun with a safe-action trigger. Often referred to by Glock as a crossover, it is part G19 and G17, something Glock is starting to do more and more.   

Glock 45 with Sentinel II micro reflex sight.
I like the looks of the Sentinel II with the optional ironside shield on the Glock model 45. [Photo: Jason Mosher]

The Glock 45 consists of a G17 pistol grip, which means it uses 17-round mags and a Glock 19 slide. Note: a 17-round mag is not why they named it the Glock 17. When Glock developed a pistol for the US Military trials, they made the Glock 19X. It wasn’t selected, but the gun had some success on the civilian market. But the Glock 19X is limited to extended magazines and is not compatible with standard G17 mags.

When Glock produced the G45, they reverted back to the “standard” version magazine well. This version may not be for everyone, but for those wanting a shorter barrel with a full-size grip, it’s a perfect choice. It also offers better balance than a Glock 17 (in my opinion) when shooting.

Another reason for this combination of a duty-size weapon is to allow it to clear a duty holster faster. This means maximum ammo capacity and a faster draw for those wearing a duty or combat holster.

Glock 45 accessories

Because of the huge aftermarket world of Glock accessories, the sky is the limit. The Glock 45 is optics-ready so you can mount just about any type of micro red dot on it you want. Glock even sends a bag of adaptor plates to help with this. Optic-height sights, extended mag and slide releases, flared mag wells, and more are all easy to upgrade on the Glock 45.

If you want to add a suppressor, just change out the barrel with a threaded G19 barrel. Having a short barrel with a longer grip helps offset the extra weight from a suppressor.

Holsters for the Glock 45 are easy to find because you can use just about any Glock 19 holster. Among my favorite is the Safariland 7360 RDS because it works with a light and optic.

Safariland 7360 RDS duty holster
The Safariland 7360 RDS duty holster (pictured here with a 9mm Glock 45) fits the Swampfox Sentinel II red dot optic. [Photo: Jason Mosher]

Safariland made a removable hood that covers the optic and flips out of the way when you draw it. My favorite setup on the Glock 45 is the Streamlight TLR-1HL tac light and Swampfox Sentinel II red dot with the Ironsides shield.   

Sig M17: Standard Issue Military  

Sig earned its bragging rights when its P320-based handgun won the US Military contract for the standard-issue sidearm.

I have always liked the P-320 line of guns. The first time I fired one, it reminded me somewhat of the 1911 “point and shoot” feel. With a handle that sits far back on the gun, it has some front-end weight, but it helps reduce recoil when fired.

Sig M17 9mm handgun.
The Sig M17 is a great shooting gun, and the recoil is surprisingly low. [Photo: Jason Mosher]

One of the biggest differences with the M17 compared to the commercial P320 is the added manual safety. This was at the request of the military, and again, it has a 1911 feel to it. I’m not used to having a safety on a gun, but this one doesn’t get in the way, so it doesn’t bother me any.

If you are used to firing 1911 pistols, this safety is easy to flip on and off as you draw. Sig also added a removable optics plate, but the rear sight is attached to it. This means the sight must be replaced when adding an optic to the gun. I wish Sig had done this differently, but that’s just my preference.

The mag release is easy to push, and the slide has a soft recoil spring, making it easy to rack a round into. For such a small slide release, it’s surprisingly easy to find with your thumb.

What makes Sig really stand out is the replaceable grip module. By removing one pin, you can pull the trigger frame housing out of the grip module. This makes it easy to replace the grip with other sizes, colors, and styles. Because of its popularity, there are a lot of companies making grip modules for the Sig P320 and M17.   

Accessories for the Sig M17

As I mentioned above, the grip module is by far the most popular feature of this gun. If you have an M17 pistol, make sure you purchase the grip module made for manual safety. Standard P320 grip modules will not work in it because they need a groove for the safety to slide in.

When I purchased my M17, it came with one 17-round mag and two 21-round mags. This is a great feature to come standard with a pistol. The extended 21-round mags extend the grip some, but not enough to bother me.

Safariland 6378 holster.
I like the Safariland 6378 holster with a paddle attachment for quick on-and-off abilities. [Photo: Jason Mosher]

For holsters, I use the 7378-duty holster that fits the Streamlight TLR-1HL. Without a light, I like the 6378 ALS concealment holster. I use the QLS system to attach the 7378 to my duty belt or drop-leg thigh holster. For an off-duty holster, I keep a paddle on the 6378 so it’s quick to put on and take off. Both holsters have automatic locking when holstered with a thumb release to draw.      

On the range with the Sig M17 and Glock 45

Which one you like best on the range will be a matter of personal preference. Sig makes a great trigger and I shoot well with that gun. It’s also a combination of the grip and balance of the pistol that makes me like it. There is very little recoil on this gun.

Because I carry a Glock on duty at work, I’m not sure which gun I would have naturally liked more. I’ve been shooting Glock pistols for more than a decade and they just feel natural to me. Glocks are accurate and comfortable as well, especially the G45.  

While I’ve fired both guns more times than I can count, I don’t shoot them back-to-back very often. Thanks to for supplying some Magtech 115-grain FMJ 9mm ammunition for the review.

After running multiple drills on the range, I found a few things I liked more with each gun. It wasn’t a big difference, but I could change magazines a little faster in the Glock 45 pistol. This may be due in part to it having a slightly flared mag well.

For speed timing, I shot a little faster with the Glock 45 as well, but this is likely because I’m more used to the reset of the Glock trigger.

Shooting the Glock 45.
The G45 has a full-length grip with a short slide, making it balance well. [Photo: Jason Mosher]

When it came to accuracy, I shot better with the Sig M17. It does have a longer barrel, but I only went out 25 yards. I started at 10 yards and moved out 5 yards for each magazine. I’m not sure I could pick a favorite, but that’s why I have both guns. They were designed for armies and built to last.

Which one is right for you?

Like I said in the beginning, both of these guns have been tested extensively and used by military and law enforcement personnel all over the world. Find which one works best for you and go with it.

Some of your decision may depend on the accessories you plan to add to the gun. For those concerned about magazine compatibility with other weapons, Glock is a great way to go. I have sub-guns, AR-15s, and other pistols that all work with Glock mags.

If you want the same gun as the military uses, go with the M17. When a company makes a product for the military, it won’t be long before it’s available in the civilian market, especially holsters, lights, and optics. There is something special about owning the same weapon the US military issues to soldiers. This is why so many people still love the Beretta, 1911, M1 Garand, and other famous guns from our military.

Whichever gun you choose, you will own a great handgun that will last a lifetime if taken care of.    

Get the Safariland Newsletter

Get the SITREP on promotions, product news and exclusive offers.

Sign Up

Find a Dealer

Find a dealer near you with Safariland’s dealer locator.