Glock 45 MOS Review: The Red Dot Special

If there's one word that is synonymous with Glock, it's reliability. Other people, like Glock themselves, have a different word they like to use: Perfection. While I use their chosen word sparingly when describing anything in life, I can say that the 9mm G45 is a reliable pistol, excellent for self-defense or just a good time at the range.

I want to repeat this is a 9mm, not a .45 ACP gun.

The Glock 45 MOS (Modular Optics System) is a crossover pistol, meaning that it has a full size grip that holds a 17 round magazine, and a shorter, compact-sized slide that encapsulates a 4.02 inch barrel.

It's kind of like a G19 and a G17 got together, had a baby called the G45, and gave us the option to mount an optic on it renaming it G45 MOS.

The cut down slide and barrel with the bigger grip is meant to help the gun conceal just a bit better while maximizing shootability. After running about 800 rounds through this G45 MOS I can say that it does shoot very well.

I'd hate to bore you, but it didn't malfunction once after running a few different kinds of ammo through it to include Blazer 115, SIG V-Crown Hollow Points, and a few other cheap brands.

I started my time by putting a couple hundred rounds through this gun without the optic installed to make sure that the gun is accurate both with the optic, and without. I'm sure most people rush to mount their chosen red dot, but I took my time.

I did this because I know someone will buy one of these guns with the intent of buying an optic for it, but due to the inherent high cost of a good optic, will have to carry it without one for a while.

Here's the pistol without the optic on it. Simply remove the plate, figure out which of the included plates you need for your optic, and mount it.

The pistol shoots great if you want to shoot it without the optic, and handles just like you'd expect.

Therefore, if you think there is a chance you'll want an optic later, buying a G45 MOS is a good idea because you can still defend yourself with it and carry it on your body as you anticipate purchasing and installing the optic.

By the way, the red dot I used for this review is the Leupold Delta Point Pro. A review on this optic will be forthcoming, as well.

I was very worried at first about the installation of the red dot because I'm not one to change anything on my guns. Not once have I ever swapped a trigger or even installed aftermarket sights on a gun by myself. But I have to say that it went smoothly.

Glock makes it super easy to switch just by figuring out which plate you need, removing the stock plate, and screwing down the right one. Zeroing is something I'll cover in the Leupold review.

With the finger grooves removed for Glock's latest iteration of pistols, the Gen 5, the G45 MOS fits my hand like it was meant to be there. I have massive hands that are usually the biggest in the room, and I can get my whole hand on this grip.

As you can imagine, this really helps the pistol stay on target because more fingers on your gun are better than less, in terms of recoil management.

Something I thought was a nice touch on the G45 is the flared mag well. I'm a huge fan of stacking as many positives on my side as possible, and even just something as small as a flared magazine that may help me reload under stress during a battle is appreciated.

Honestly, this is something I wish more manufacturers would do.

Another feature I'm a fan of that's a recent entry for Glock's pistols are the front slide serrations. Again, not the biggest deal, but I want to stack as many things on my side as possible and having an extra touch point for getting the gun back into action can only be seen as a good thing.

At first, I racked the slide by the rear serrations as I normally would before I put the optic on. After it was on, I found myself either going to the front serrations or going to the red dot itself.

You can notice the muzzle of the G45 MOS below, with the front slide serrations.

The trigger has the blade safety other pistols do, but this trigger feels good. I'd call it somewhere in the neighborhood of a 5 pound pull with a crisp break and a clear improvement over previous Glock triggers (to me, anyway).

Here is an up close and personal look at the trigger and blade safety:

Also notice the magazine release which is reversible and probably my only gripe about the G45 MOS. I wish it stuck out just a bit more so I didn't have to adjust my grip to eject an empty mag, but such is life.

I do want to point out this is a problem I have with most guns, and I understand why this one is the way it is. If it stuck out any further the dimensions of the gun effectively change from having an overall width of 1.34 inches to just to a bit bigger.

While on the topic of dimensions, they are as follows from Glock's G45 page:

1 Length (Overall)** 189 mm | 7.44 inch
2 Slide Length 174 mm | 6.85 inch
3 Width (Overall) 34 mm | 1.34 inch
4 Slide Width 25,5 mm | 1.0 inch
5 Height incl.Mag. 139 mm | 5.47 inch
6 Line of Sight (Polymer) 157 mm | 6.18 inch
Line of Sight (Steel) 156 mm | 6.14 inch
Line of Sight (GNS) 155 mm | 6.10 inch
7 Trigger Distance** 70 mm | 2.76 inch

Other great improvements included with the G45 MOS are the modular backstrap system, the Glock Marksman Barrel, and the nDLC coating.

Overall, I think the G45 MOS is a great gun. It shoots and handles great with its full size grip and can be used in either configuration. If you're on the fence about a red dot and may move in that direction in the future, this is a great, shootable option for you until you get to that point.

The MSRP is nothing to sneeze at being $745, but the street price is lower in the $600s.

Here are a few more pictures that I wasn't sure were to put inside the actual review:

About Joshua Gillem

Josh is a lifelong practitioner and student of the gun. He grew up shooting/hunting with his dad, and was given his first gun, a 12 gauge shotgun, when just a small boy. After high school, he joined the Marines where his love for firearms blossomed as he qualified with an M16A2, an M9, and a 240G. Josh has been writing about firearms and tactics for several years, owns the blog Gunners Den, is a staunch supporter of the Second Amendment, and believes that each individual person has the right to self-defense by any means necessary. Currently residing in gun-friendly NC, he carries a concealed gun on a daily basis, even in his own house.


  1. Jeffry on November 10, 2019 at 5:50 am

    I will look at it!

  2. Mark on June 14, 2020 at 9:07 pm

    Thanks for the info.
    I’m looking at different guns & the Glock 45 MOS sounds like what I’ve been trying to find. A lot of the guns I’ve looked at are good for concealing, but I’ve got big hands & to small to hold well. This may be the one,

  3. Michael Nix on September 21, 2020 at 10:25 am

    Why does the 45 MOS have a different part in the trigger housing than either the Glock 45 or 19X?

  4. Jennifer Dudley on September 23, 2021 at 7:46 am

    I’m looking for my first gun the Glock 45 mos seems like the one I’m looking for do you think that would be good for your first gun

    • Tara W on December 26, 2021 at 4:56 pm

      My Glock 45 MOS keeps jamming. I’ve put about 600-800 rounds through it. It doesn’t do it all the time, but enough that it concerns me. What should I do?

      • Greg Westbrook on July 7, 2022 at 3:55 pm

        Send it back if not too late or have a good reliable gunsmith deburr (sharp edges in the loader eject mechanism left by machining processes.

    • DJ on February 17, 2022 at 4:46 pm

      I purchased a G45 9mm as my second firearm. My first was a Taurus G3C as a CC weapon. I have found that my love for the G45 is second to none. I didn’t think a “full-sized” firearm would be that much different than a compact, but it is for me.

      The G45 is easier to handle and control than the Taurus, thus making my shooting more accurate. If you can get to a range that has one to rent, that would be the recommedation I would make.

  5. Arnold on February 13, 2023 at 4:04 am

    I bought a G45 but it doesn’t have the plate on too of the slide so it can’t beban MOS model correct? I want to put a Holosun 507K green dot on it.

    • Matthew Maruster on February 13, 2023 at 6:11 am

      It doesn’t sound like you have an MOS, but that’s not necessarily a bad thing. You can send your slide to companies that will direct mill your slide to direct mount your Holosun, which is a better method than the MOS system IMO.

  6. Brad Peterson on February 17, 2023 at 11:35 am

    What company has the best price?

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