GLOCK 40 MOS 10mm Auto, longslide, size matters.

Glock 40 MOS-2 (2)

Glock 40 MOS 10mm Auto review

GLOCK, in my opinion, stepped up their game SHOT show 2015 with the GLOCK 40 MOS in 10mm Auto. If you have been reading rangehot any at all or know me even a little, you will know I love the 10mm Auto as much as a man can love a cartridge.

You can see my 10mm Auto ballistic test using the GLOCK 20, 10mm Auto by following this link. The 10mm Auto teetered after the FBI abandoned it for the .40 Smith and Wesson but due to a few manufactures’ insight, such as GLOCK , chambering their pistols in the powerful cartridge, the 10mm has taken hold.

My GLOCK 20 has been boringly reliable since I bought it but, always looking to experiment, I bought a factory 10mm Auto six inch barrel for my G20 and begin to experiment with the chronograph and ballistic gel. There were noticeable gains in velocity and that translated into better ammunition performance in ballistic gel. That was well and fine but the pistol looked a bit odd with that 1.6″ of barrel sticking past the slide.

So, someone sitting in the GLOCK think tank was reading my mind and WHAM! there was the GLOCK 10mm longslide at the 2015 SHOT show.  In addition to the longslide, GLOCK incorporated their MOS system. MOS stands for Modular Optic System and has been included on several of their pistols. The MOS system allows you to mount popular optics to your pistol via a pre-machined recess at the rear of the slide. Using one of the five included adapter plates and a two Torx fasteners you can mount your optic without having to remove the rear sight or have any machining work done. If you choose to run your pistol with iron sights, it ships with an insert matched to the slide that fills in the recess. Currently the adapter plates can accommodate  Eotech, Doctor, Insight, Meopta, Trijicon RMR,  C-More, and Leupold Delta Point. The instruction manual tells you which plate for which sight.

Glock 40 MOS-11 Glock 40 MOS-12

The longslide adds more benefit than just esthetics. With a longer slide you have a longer sight radius and that helps a great deal with a proper and more specific sight alignment. If you handgun hunt, many states require you to have at least a six inch barrel. So, if you plan to hunt with your GLOCK, why not take advantage of the added sight radius along with the added velocity and accuracy?

I put in a request at SHOT for a 40 MOS test sample due to the fact it was everything I like about GLOCK and 10mm packaged in a single pistol. When it was released to distributors I got my test sample. I immediately took it out and ran a few magazines through it and compared it directly to the GLOCK 20 with the six inch barrel. The 10mm Auto does have a sharp recoil but is manageable with proper technique.

Here is one of my students shooting her GLOCK 29, a subcompact 10mm Auto and these are for real 10mm Auto loads, so you see, even in a subcompact the gun can be controlled.

Glock 40 MOS-14

With that said, the longslide helps tame the recoil, and now with the Gen4 pistols shipping with optional backstraps for a more custom hand fit and pick of a beavertail size it certainly turns a controllable pistol into one that is plush to shoot. You can see there is plenty of real estate on the slide. Accessory rail is standard on this as all full size and compact GLOCKs since the third generation. I think accessory rails are a solid option but on a pistol such as this that would be ideal for hunting or trail protection, a rail is a must.

Glock 40 MOS-3

What it comes with, not shown is the lock, instructions, and standard polymer case.  You can see the other backstraps, the two spare magazine, magazine loader and the four adapter plates for optional optics. Though GLOCK includes a single Torx L shaped wrench that fit the included screws, I would get a nut driver in that same size and use it over the included wrench.  There is also a small flat head screwdriver for the adjustable rear sight.

Glock 40 MOS-10 Glock 40 MOS-1

Rear GLOCK sight adjustable for windage and elevation. I can also be drifted in the dovetail. You can see the filler plate in place here just above the cocking serrations as well as the backstrap I favored of the options.

Glock 40 MOS-9

The Gen4 GLOCKS have updated stippling, a little more aggressive but still comfortable. Also as with Gen4s the magazine catch is interchangeable from left or right.

Glock 40 MOS-6 Glock 40 MOS-7

The trigger broke, on average, just under five pounds. It seemed little improved over what I was used to with GLOCK, but it is still a GLOCK trigger.  My biggest complaint was the slide stop did not have provisions to be released with your thumb. GLOCK makes a factory slide stop with a shelf for thumb and that is always the first thing I change. If I were to change one thing, it would be the slide stop. With that said, the slide stop worked as it should, even with the Gen3 magazines.

I ran a few magazines through the pistol to get a feel for it and then went to the twenty-five yard line for some accuracy testing. Once that was over, I got a pile of factory rounds and my favorite 10mm reloads and went to the range to really wring out that pistol.

Glock 40 MOS-1-2

The GLOCK 40 MOS detail strips just as any other Glock. Easy as pie.

Range day.

Glock 40 MOS 10mm Auto

Accuracy chart, 3 rounds fired from a rest at 25 yards.


My buddy Jay trying out the 40 MOS.



The GLOCK 40 MOS, as all other GLOCKs I have experience with, is reliable and employes the same manual of arms, but that is about where the similarities stop. Compiling the already popular MOS system with the integrated accessory rail, and the six inch barrel with the already proven platform of the GLOCK 20 you get a 10mm Auto pistol with the same capacity but increased velocity, sight radius, and the option of easily adding optics. Now the GLOCK 20 is a bit large for concealed carry and with the increased slide length, the GLOCK 40 MOS would not be your ideal concealed carry platform. That being the case, this pistol was not designed for that, but really shines for handgun hunting, either primary or backup. I also see it as an ideal pistol for trail or camping defense against two and four legged predators. The Gen4 GLOCKs ship with three magazines so you have plenty of backup magazines right out of the box. As you saw in the video, the GLOCK 40 MOS fits nicely into holsters for the GLOCK 20 with an open end, or at least that was what I found with my couple leather and Kydex holsters. As you also saw, about the middle of the video portion of the review, I shot a local tactical match with the GLOCK 40, and even though I was not completely familiar with the new pistol  I placed in the top five out of about twenty-five people, so not bad at all for my first run with a brand new pistol. You don’t have to worry about making power a factor with the 10mm Auto as well, and to me it is easier to shoot than many pistols in .45 Auto. So with adding a red dot and a few modifications I could see this pistol as an excellent match pistol. With all that you see here, I believe GLOCK hit a home run with the 40 MOS.

Glock 40 MOS-1-3

Redfield Accelerator red dot sight mounted, the Accelerator is not readily compatible with the MOS system but I was sent one to review and with the included Accelerator plate the sight securely mounted.  This will give you an idea of what the GLOCK 40 MOS looks like with a red dot mounted. So far that red dot has worked well but that review has just began.


9.49 in./ 1.28 in.

Sight Radius
8.19 in.

5.47 in.

Barrel Length
6.02 in.

Weight unloaded                                                                                                                                                                   28.15 oz.

Trigger pull and travel                                                                                                                                                          5.5 lbs.-0.49 in.
Barrel twist and rifling                                                                                                                                                      right hand, hexagonal/ /1 turn in 9.84 in.

Magazine capacity                                                                                                                                                                   15 rounds




37 PSR Gun Club

By Hunter Elliott

I spent much of my youth involved with firearms and felt the call early on to the United States Marine Corps, following in my father's and his brother's footsteps. Just after high school I enlisted and felt most at home on the rifle range, where I qualified expert with several firearms and spent some time as a rifle coach to my fellow Marines. After being honorably discharged I continued teaching firearm safety, rifle and pistol marksmanship, and began teaching metallic cartridge reloading. In the late 1990s I became a life member to the National Rifle Association and worked with the Friends of the NRA. Around that time my father and I became involved with IDPA and competed together up until he passed away. I began reviewing firearms for publications in the mid 2000s and have been fortunate to make many friends in the industry. Continuing to improve my firearms skills and knowledge is a never ending journey in which we should all be committed. I am also credited as weapons master on a few independent films.

30 thoughts on “GLOCK 40 MOS 10mm Auto, longslide, size matters.”
  1. Nice to see glock thinking out side of the box, it’s what it takes to keep a competitive lead in the ever so changing of world of guns. BTW gotta love the can of Vienna sausage in the background no range time is complete without them lol good stuff

    1. Thank you Josh, and I agree. Glock is doing some good things though it took me a bit to get used to their pistols I am now a fan.
      Man you got to have snacks at the range, right?

  2. Great article, easy to follow and photography awesome. When reading this one can tell you have put a lot of time, effort and thought in this article. Keep up the good work.

  3. The Glock 40 will be my next handgun! I kinda disagree about one thing I read here about using a 20 for a carry gun. I am a big guy and I carry a 20 every day. Well just to be fair it’s because I have not bought a 29 yet, The 40 comes first then the 29. I took 3 Whitetail deer last year with my 20 also. It’s hard to beat a 10mm in my book.

    1. I also carried the Glock 20, and in winter if I dressed for it, I could carry that pistol. I bought a 29, and man that concealed so much better. When I carried the Glock 40 MOS, the muzzle stuck past my shirt but I am only 5′ 7″.
      A larger man, dressed for it, could carry the 40 but that is a lot of pistol to draw.

    1. Thank you very much sir, I appreciate you taking the time to let me know what you thought on the 40 MOS article. The 40 really exploits the 10mm Auto and is worth having for sure.

  4. Hi Hunter,
    Great review. Just curious, are the frames from the Glock 40 and Glock 20 the same and interchangeable?

    1. Yea and no. The 20 slide will jive with the 40 receiver but the 40 slide will not jive with the 20 receiver. The 40 receiver has a bit of the dust cover removed to accommodate the larger slide at the dust cover. Though a bit of work with a sharp knife and they would both work.

  5. Thanks for taking the time to do his review, sir. The 10mm Auto is king!!

    My last three deer kills while Deer hunting have been to well placed full power, heavy projectile 10mm slugs auto rounds sent through the animals vital organs at ranges from 5-7y out to maybe 30 yards. You put it whence it needs to go, the 10mm will do the rest on Deer (even large Deer) and big hogs.

    I hsve a fusion 1911 longslide I had Fusion build for me a few years ago. My favorite possession.

  6. I have an opportunity to purchase a Glock 40 MOS as part of commemorating the Alaska State Troopers 75th anniversary. These Glocks well be specially engraved. Your article was very well done. I have decided that I will be purchasing my first 10mm handgun.

    I do a fair amount of back country hiking, fishing, ATV & snow machine time. I feel this pistol well be easier to carry than my .44mag revolver. Would you suggest a factory round that would maximize power for close range protection.

    Thank you,


    1. Thank you for your kind words John. I believe you are correct in choosing the Glock 40 over the 44 Magnum. While the .44 Magnum is more powerful you will be limited to six rounds and a slow reload. With the Glock you have 15+1 and a much faster reload. For factory 10mm that carries a lot of energy I would take a look at Double Tap ammo. They make some serious defensive ammo that is safe to shoot and will get you very close to .44 Magnum energy in a 10mm. Thank you again.

  7. I just purchased a 40 MOS and the Redfield Accelerator. What plate did you use? I had to grind off the nipples on one plate and stack 2 plates together to make it work temporarily.

    1. You have to use plate 05 along with the plastic plate the Accelerator comes with. You will have to trim the plastic plate the Accelerator comes with so it will fit flush in the slide. I had to get longer screws that went through the Accelerator and the plastic plate, and tightened to the small holes in 05 plate. You have to tighten the 05 plate first and put it together from there. The pegs in the plates will all line up once you trim the plastic plate. You can use the 05 plate as a reference on how much to trim.

      1. Do you think they will ever make an Accelerator Plate as I purchased the same sight with the MOS and am having the same issue.

        1. The unofficial word I got was probably not. Leopold owns Redford and as I understand it Leopold is pushing the Delta Point for the MOS system. In keeping the plates different they will sell more of the more expensive sight. I was told the Redfield Accelerator would also work and it was not until I tried to mount it I saw it would not and Leopold confirmed it via phone I then decided to make it fit and it has worked very well.

  8. I picked up one of these Glock 40 MOS 10mms and can’t say enough good things about it. It’s like having 15-rounds of .357 all in a semi-auto lighter and not much bigger than a 1911. The only dimension actually larger than a 1911 is the overall length (just under an inch longer than a 1911), but you’re getting a full inch more in barrel.

  9. First off thank you for your service Sir. I was looking at the 40 a few months back on line thinking I would like one as I have the 29sf and love it. I went by the local gun store on Monday and they were in stock so yes I picked one up. I can’t wait to take it to the range. Great review keep up the good work.

    1. Marcie, thank you very much for your kind words. I appreciate you taking the time to let me know what you thought about the Glock 40 review. You are going to love that pistol, I promise. I have a Glock 29 as well and it is a fine pistol for sure, but the 40 is soft shooting and accurate. Please let me know what you think of it once you break it in.

  10. I just ordered a Gen 4 Glock 20. I see several older videos saying the 40 slide will not fit on the 20 but they were all Gen 3’s. It looks like the Gen 4 lower is the same as the 40 lower and will accept the 40 slide. ???????? Any chance or updates ? Thx Rick

    1. I came to find this review in 2022. Great stuff. I recently picked up a Glock40 for a big bear country backup while hunting. I threw a Triji RMR on it but haven’t had the time yet to warm the barrel up. I much appreciate your in depth review.
      Semper Fi Brother and keep up the great reviews.

  11. love mine-already had a 6″ barrel and a 9″ barrel for my other Glock 10mm-but this is a very nice gun.

  12. I have just read this review, and would like to comment.
    I have several Glocks, 2 mod 35’s and a 40. With all 3 I have replaced the barrels with a KKM barrel, and the triggers with the Edge competition. The Edge trigger is not for a duty pistol.
    One of the 35’s is a gen 4 MOS, the 40 is a MOS. Both of the Mos pistols have a Leupold delta point pro (2.5). The reason for the KKM barrels is that they have a match chamber, and with the gen 3 model 35, the barrel really improved the groups and the brass condition after firing. My daughter shoots the model 35’s far better than I can. The 40 ammo is reloaded with Hornady 180 XTP, or HAP. The XTP is VERY accurate at 13.2 grains AA9, or 10.5 grains AA7. Velocity with 13.2 AA9 is 1276 avg 15 rounds with Labradar Chrono. The AA7 load is avg 1207 fps.
    These are very accurate, and the 6 inch barrel does step up the velocity. Recoil is good.
    The Leupold delta point at 2.5 makes the shooting fun. The only thing about an MOS is the co-witness sights, which are high, and you have to search for a holster.

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