Test: GLOCK 34 Gen5 MOS in caliber 9mm Luger

More than 8 years after the first versions of the Gen4, GLOCK launched the new 5th generation of pistols. The most obvious difference to the Gen3 and Gen4 is the lack of finger grooves. As representative of the new generation, our testers chose the GLOCK 34 MOS. As usual, the model 34 is the slightly extended sports version of the GLOCK 17. 

GLOCK 34 Gen5 MOS rear sight
The MOS milling for MRDS mounting plates is concealed under the cover in front of the rear sight.

The Modular Optics System (MOS)

The MOS acronym stands for Modular Optic System: with the MOS the flat milling in front of the rear sight accommodates one of four supplied mounting plates on which a small red dot sight can be attached. Unfortunately, the factory rear sight and the front sight are not visible in the sight image afterwards. Never mind: for no other pistol, with the exception of the 1911, there is a wider range of alternative sights than for GLOCK, and you can easily find a silencer sight of suitable height if required.

This is the 5th generation’s "34"

Glock 34 Gen5 MOS disassembled
The sports model 34 sports all detail changes of the new Gen5 GLOCKs. Disassembling the pistols is child's play. And many assemblies doesn’t require to be stripped. Unfortunately, the gun has to be first uncocked - and that’s only possible by pulling the trigger.

With the new GLOCK 34 Gen5 MOS it is no longer possible to have cut slides: the large opening on the top of the slide, typical of older 34s, is no longer necessary. Due to some modifications in the slide itself, the Gen5 upper component still weighs almost exactly the same as the slide of an older GLOCK 34. The slide stop lever on both sides of the frame on the GLOCK 34 is slightly larger and wider than on a typical service model such as the 17 or 19. Apart from that, the 5th generation 34 MOS does not differ much from the models from Deutsch-Wagram that are not designed specifically for sports shooting. Among the Gen5 most important innovations, besides the second slide lever, the nDLC hard coating instead of the previously used Tenifer coating and the GLOCK Marksman Barrel (GMB) featuring a new inner profile and muzzle crown. GLOCK had already introduced the pleasant non-slip RTF2 grip pattern, the improved magazine release and the exchangeable backstraps with the Gen4. The captive double recoil springs used to be typical for sub-compact versions. Today they can also be found in all full-grown variants such as the 34 model. The mounting rail in front of the trigger guard isn’t Picatinny standard.

The GLOCK 34 MOS on the firing range

The muzzle of the GLOCK 34 Gen5 MOS
The Gen5 GMB barrel features a new muzzle crown and inner profile.

Due to the Safe Action trigger system, which has been developed for easy to use and still more drop- and operator-safe combat pistols, it is not simple to achieve top groupings with GLOCKs. In this case, the best group diameter at 25 m was 58 mm (Magtech JHP), with one flyer almost doubling the shots group (-11 points). 

Regardless of the ammunition power or bullet selection, there was nothing to criticize about the functioning of the GLOCK 34 (-1 P.), the minus point in the cycling and safety area being due to the disassembly requiring the user to pull the trigger. Three out of ten points were deducted by the testers for the safe action trigger: the Model 34 MOS is primarily a match pistol, and the Safe Action trigger leaves something to be desired even in dynamic disciplines (-3 P.). The grip design, on the other hand, obtains a full score (-0 P.), and the same applies to the concept and ergonomics of the controls, which also take left-handers into account (-0 P.). The sighting concept of the 34 MOS did not receive a point deduction only because GLOCK directly provides four mounting plates for the pistol - the best option for experimenting with various Red Dots (-0 P.). The plastic factory sights alone would not have been sufficient to get five out of five points. In the fit and finish area, the testers criticized the loose fit between frame and slide as well as the sharp edges on the magazine well. Otherwise, the 34 shows itself to be accurately machined on the inside (-2 P.). 

GLOCK 34 Gen5 MOS review

Accuracy (max. 50 points) 
39 points
Cycling/safety (max. 10 P.) 9 points
Trigger characteristics (max. 10 P.) 7 points
Grip design (max. 5 p.)5 points
Controls (max. 10 P.) 10 points
Sights (max. 5 P.) 5 points
Fit and finish (max. 10 p.) 8 points
Total points (max. 100 P.) 83 points
Test result   
very good
5 out of 6

The GLOCK 34 Gen5 MOS at a glance


GLOCK 34 Gen5 M.O.S.
Price:995 euro
Caliber:9 mm Luger
Magazine capacity:17/19 + 1 cartridges
Barrel length:5.3“ / 135 mm
Dimensions (L x W x H):8.7 x  1.37 x 5.47 in / 222 x 35 x 139 mm
Trigger pull:79 oz / 2250 g
Weight:26 oz / 740 g
Features:Polymer frame, striker fired, GMB barrel, ambidextrous controls, polymer sights

GLOCK 34 Gen5: wrap-up

All in all, the Gen5 innovations and the concept of optical mounting system left a well thought-out impression – the GLOCK 34 Gen5 MOS will pleasure all those on the shooting range who appreciate the practical design, but want a plus in shooting comfort compared to a basic version such as the GLOCK 17.

Further information about the GLOCK 34 Gen5 MOS can be found on the manufacturer's website.

all4shooters.com already published tests of the following pistols:

This article is also available in this language: