Gun Review: GLOCK 34 MOS
Glock 34 MOS Gen 5 FS (image courtesy JWT for
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The GLOCK 34 MOS Gen5 FS. I know what you’re thinking. “It’s just like the new GLOCK 17 MOS, only longer.” And in fact, it’s just like the new GLOCK 17 MOS, only longer.

The new G34 may be like the other Gen 5 GLOCK guns, but there are a few changes to previous generations. Most obviously, the Gen5 G34 has ambidextrous slide stop controls. They’re also oversized on the G34 as compared to other models, as is the reversible magazine release (which is only slightly larger). Those finger grooves are gone, too.

There are still larger options available for competitive shooters, but I’d advise anyone using the firearm as a self-defense or duty tool to stay away from those, as a-less-than ideal grip can leave you with an accidentally dropped magazine.

Gun Review: GLOCK 34 MOS

You’ll also find that the G34’s grip doesn’t have the small moon cut in the front, unlike other Gen5 models. The magazine well is also slightly funneled, with a small amount of flare. GLOCK did this pretty well, and I had no issues with magazine hanging up while blindly inserting them into the flared magwell, something that did occasionally happen to me with previous models.

Gun Review: GLOCK 34 MOS
The G34 Gen5 MOS’s long sight radius (image JWT for TTAG)

This particular pistol came with the polymer sights that are standard on GLOCK pistols. They’re prone to breaking and rounding over time with regular use. Fortunately, there are steel and low-light options available from the factory as well.

The inclusion of four additional back straps is big plus. With the largest backstrap, which includes a healthy beavertail, the placement of my finger on the trigger is ideal. I have size large hands, and the standard grip always leaves me either pulling my finger to the side or gorilla gripping the trigger. The package also includes a handy “punch” and pin to complete the swap out.

Gun Review: GLOCK 34 MOS

This version of the GLOCK 34 includes the GLOCK Modular Optic System (MOS). Like many other optics-ready models offered, GLOCK includes several (four) mounting plates to mount a variety of popular pistol optics. That means if you choose to mount a red-dot style pistol optic, you won’t have to have your slide milled to do it.

It also means that, in comparison to a custom milled slide, the optic will sit slightly higher on the gun. Based on your optic and round of choice, your iron sights may co-witness, or they may not.

I’ve tried it time and time again, and I don’t shoot any more accurately or faster with a pistol optic than without. But that only counts for shooting in daylight. At night, it’s much easier to see the red dot as the dot makes for a single plane of focus. Now you don’t have to see your sights and the target in the light, just the target. Of course, tritium sights work well, just not as fast as the optic in low light.

Gun Review: GLOCK 34 MOS

Unsurprisingly, I had zero failures of any kind with this gun. I fired mostly 115gr and 147gr Armscor FMJ rounds from the pistol, as well as a few magazines of home rolled HPs and Speer’s 124gr HP Lawman ammunition. Using the three supplied magazines, I fired a total of 500 rounds through the gun with no issues whatsoever.

As I do with most lightweight striker fired pistols, I intentionally fired the gun from less than optimal positions and grips. One that often gets my Gen3 G19 GLOCKs to misfire is to stand bladed 90 degrees to the target, put my firing hand across my body with my forearm parallel to the ground and near my belt, and then fire the gun with a fairly loose hand and wrist. I often get failures like this, or if I’m in a similar position, but laying down.

My G21SF doesn’t short cycle in this position, and neither did this G34. Ideal hand position and grip strength isn’t necessary for the gun to function, a feature I find valuable on a weapon intended for duty or self-defense.

Gun Review: GLOCK 34 MOS

Off the bench, the Gen5 MOS is a solid performer. At 25 yards, several brands of ammunition shot all around the 2” mark. Averaging four shot strings of five rounds each from 25 yards off a rest, the GLOCK 34MOS Gen5 shot the dirt cheap Armscor 115gr FMJ at 1.7”

Gun Review: GLOCK 34 MOS

The GLOCK Marksman barrels are just fine, but what really helps with that level of accuracy is the seven-and-a-half-inch sight radius and a vastly improved trigger. I’ve said it before and I’ll double down on it. If the new GLOCK triggers were the ones they put on the previous generation’s models, there would never be the aftermarket GLOCK trigger market we see today.

Breaking at 5 lbs, but with little grit and creep compared to earlier models, there’s no reason to swap out this trigger with an aftermarket brand. Unless you’ll be using the G34 MOS purely a race gun, the pistol’s trigger is great as it is. And it doesn’t just help off the bench.

Gun Review: GLOCK 34 MOS

The GLOCK 34 Gen 5 absolutely hums along in fast fire. Even though the gun itself weighs fairly little, the 8-inch plus nDLC finish slide helps to keep the muzzle down. The barrel itself is actually 5.31”, about 1/3rd of an inch longer than a full-sized Colt 1911. That long slide and barrel length, combined with a long sight radius and a good trigger makes the gun blazingly fast.

Fast fire is where the GLOCK 34 really shines. Although originally created to win competitions, the full size 34 has rapidly and rightly become the sidearm of more than a few law enforcement agencies.

I know folks who carry the gun OWB as their everyday carry pistol and with the Gen5 version, I think that number is going to get a lot higher. I was really impressed by how well the muzzle stays down, and how easy it is to control, especially as a stock factory gun.

Gun Review: GLOCK 34 MOS

Yup, it’s big. But really, it’s no larger than the 1911 Governments I’ve carried every day for years. And it’s a lot lighter. With the right holster and the right dress, everyday carry is completely doable. Duty carry is easy.

Gun Review: GLOCK 34 MOS

GLOCKs have changed at a glacial pace since their original design. The incremental improvements of the Gen5 models are all as a result of this process, but this is the first GLOCK generation that feels like it’s a big step forward. The trigger is vastly improved. It’s finally ambidextrous. The backstraps are a good step away from “one size fits all” GLOCKs, and the inclusion of optics mounting plates catches the GLOCKs up with the competition.

Gun Review: GLOCK 34 MOS

What sets the GLOCK 34 Gen5 MOS apart is how well all of that comes together in a fairly lightweight, but long-barreled version of a competition/duty gun. It’s easy to shoot, highly customizable, and fast as all get-out. If these were the GLOCKs I’d seen 20 years ago, I’d likely be EDCing one today.

Specifications: GLOCK 34 MOS Gen5 FS

Caliber: 9X19mm
Barrel Length: 5.31 inch
Length (Overall): 8.74 inch
Slide Length:  8.15 inch
Width (Overall):  1.34 inch
Slide Width:  1.0 inch
Height incl. Magazine:  5.47 inch
Sight Radius (Polymer):  7.52
Trigger Distance:  2.76 inch
Weight with empty magazine:  26.21 oz
Magazine Capacity : 17 / 19 / 24 / 31 / 33
MSRP: $899 (found online for $720 and up)

Ratings (out of five stars):

Style and Appearance * * *
It looks like a GLOCK.

Customization * * * * *
You can already change anything on a GLOCK. With this version, some of the biggest changes you’d want to make are factory-included.

Reliability * * * * *


Accuracy * * * 1/2
For a pistol with an 8.15” slide and a 7.52” sight radius, I’d have liked to seen a little better. Still, sub-2” groups for every round I tried is better than average.

Overall * * * *
The only thing that kept this gun out of the five star category was the accuracy score. It has nothing to do with the fact that it’s just as homely as every other GLOCK. For the speed it sends 9mm pills downrange, I’m willing to overlook that. The new G34 is certainly not cheap, but GLOCK did great with the Gen5 guns in general, and particularly well with the G34 MOS.

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  1. “You’ll also find that the G34’s grip doesn’t have the small moon cut in the front, unlike other Gen5 models.”

    What’s the logic in not having that cutout? I find it *highly* useful.

    In 10mm, that would be *very* interesting….

    • Personally, I HATED that cutout, and was extremely pleased when they got rid of it, as I had a gen 5 g34 MOS like this for awhile. I had a gen2 g23 some time ago that had the same cut out, and it ripped my finger up under recoil. Not as big a deal with a 9mm, but I appreciated it all the same. I realize they’re there to help with forceful mag removal, but they really should have put coutouts/divots on the SIDES of the grip for that, like most other companies that do them.

  2. I must be missing something here “One that often gets my Gen3 G19 GLOCKs to misfire is to stand bladed 90 degrees to the target, put my firing hand across my body with my forearm parallel to the ground and near my belt”

    How can your arm be parallel to the ground and be near your belt? Is this while kneeling?

    • Parallel doesn’t mean near. I don’t know how else to explain this. The position could be made standing, kneeling, or even laying down.

        • Parallel to the ground, near his belt…as in from the hip.
          I don’t understand how you guys are missing that. Standing straight up, elbow down at belt level, forearm 90 deg to rest of arm (Parallel to ground)… and there you go!

  3. Been putting it off for far too long. But I have to sell something in order to justify buying what will end up being a 1500+ Project. I just don’t shoot enough, I have thousands of rounds of ammo, but don’t shoot since some old broad hit me, driving on the wrong side of a main road. Broke several disks and tore my rotor cuff detached 2 tendons. I keep pushing it off because I know how bad the surgery and recoup times are.
    Here’s a free tip, if you want your gen 4 glock to shoot as good as one with a 200+ trigger job, just put in a gen 3 Trigger assembly and a connector from Ghost called “angel”. It’s a differet gun now, I had tried different connectors and springs, and it still felt like crap. I realized that gen 4 dimple was a problem, and knew the gen 3 would work I changed to the lighter plunger spring, kept the rest stock, then got an email from Ghost about this new Angel connector. It sounded like bull, but for 20 bucks who cares, Let me tell you something after the 25 cent trigger job, the Angel connector, and the gen 3 trigger and rod assembly, it’s a 4 lb trigger with no stacking and that bump is gone too, it feels like I spent a thousand bucks on one of those ZEV or Tarran upgrades. Just try it for 40 bucks you can buy everything.

  4. Glock has been milking the niches for so long, they’re having to find niches within the niches at this point.

    • But still no G19 frame with 17 slide, unless you modify the frame of a 17 or buy a gen 5 G19 and G17 and put the 17 slide on top.

  5. I think backstraps have become like cupholders were in the 90s. Of you cant actually mprove something… just add more cupholders/backstraps.

    • I mean different people have different size hands and proper finger placement on the trigger helps accuracy so I’m all for them

    • They usually make a difference for me. Some pistols more than others. This is one of those, as was the FNX Tactical 45.

  6. I think I like the Gen 4 better. Dont mind the finger grooves and I dont like the flared butt.

    MOS is lost on me. But these long slides are a lot of fun to shoot.

    We would have to have open carry before I would EDC one.

  7. I’m not being snide but what’s the major benefit of having such a strangely dimensioned handgun? Is it mainly the longer sight radius? Surely not the velocity increase in 9mm. Just seems like a weird step towards being a pistol carbine…

    I guess if you’re not worried about concealability “why not” is a reasonable approach to length of a gun up to a certain point where it becomes end-heavy or difficult to maneuver\shoot with one hand…

    • 1 – velocity increase allows the use of lighter recoiling loads while still making power factor for the class
      2 – longer slide/barrel reduce muzzle rise and absorb recoil – allowing faster fire
      3 – longer sight radius reduces user error

    • This is about the same size as a 1911 or a M9, so it’s hardly half way to a carbine size wise. As for why Glock chose these dimensions for their pistol, it is as others have noted a competition oriented gun. Many of the organizations like IPSC or IDPA have a ‘box’ that a pistol has to fit into to be legal for whatever classification you are competing in. It is usually to your advantage to pick the largest gun that you can get away with due to the longer sight radius, reduced recoil and larger gripping surface available on a bigger gun.

  8. First I’ve ever heard of 1.7 inch groups at 25 yards being 3/5 stars for a production (or even a custom) gun. That’s some serious nit picking.


    • I thought I would be called out for 3.5 being generous for a competiton focused gun with a 5.3″ barrel. This is, after all, Glock’s premier target and competiton model.
      If you look at my other reviews, you’ll see 5 stars for accuracy in a full frame gun is hard to achieve. Still, Bill’s Custom Automatics 1911 is my standard at 3/4″ average 5 round groups at 25 yards using commerical ammo. That got 5 stars. I gave my stock Glock 21 a 3, as would I my stock Colt Series 70 1911s. 3 is not bad. 3 is average. This gun is above average for it’s class. But not by much.

  9. I wish somebody would show chrono results with the longer barrel. I have the older G17 and it makes *almost* .45acp power using the 147 grain bullets. Regular 9mm ammo is on par with the 40 cal. This is my tinfoil hat “20 shot end of the world gun”

  10. “It’s just like the new GLOCK 17 MOS, only longer.”

    Or is it just like the G17L, with MOS?

    There’s such a dizzying variety of black bricks, I can’t keep up.

  11. I dont like how the mos moves the rear sight back. Limited sight options. Basically have to keep plastic sights or get dawsons otherwise thell hang off the rear. Dont know why glock wont release a g34 gen5 without MOS.

    Also u think glock will stop making the original g35gen5 they made without front serrations. Cause that the only difference besides the half moon cutout.

  12. JWT this is off topic, but I’m wondering when we are going to see your review of the PTR-91? You recently mentioned that you use one as a truck gun and noted in your review of the M&P10 that it is a favorite of yours.

      • Maybe my search skills are weak. The only thing I can find here is a review of the Century C308 CETME clone. Which is kinda like everything else Century builds. Either you get lucky and it works, or it doesn’t.

        Besides the fact that I enjoy your reviews I’d be interested to know why you picked the PTR. They certainly seem well built and are reliable, but the size, weight, and generally poor trigger work against them compared to say a M&P10 Sport.

        I admit I keep looking at them. Besides their history as one of the great Cold War era battle rifles they are still reasonably priced compared to a FN-FAL. I also think they are more appealing now that newer versions have a welded on optics rail and a paddle mag release. The GI contour barrel is also nice vs the heavy profile PTR used to put on everything.

        I’ve got 10 like new G3 magazines I couldn’t pass up for $4 each. Talk me out of buying the rifle that goes with them.

  13. Was gonna stick with the 34 Gen 4 mos but could only find the gen 5 in mos let me tell you when I say I’m ecstatic about the trigger, accuracy, quality of the polymer & finish of this pistol 💯I popped on a Vortex Venom 3M dot & I’m shooting quarter sized groupings converging around a tennis ball-sized target center @ 20 yards👌 no one comes close
    to this at the range 🤣🤣🤣


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