The Glock 40 is the Austrian company’s foray into the handgun hunting market traditionally dominated by large-bore revolvers.
There is nothing traditional about this Glock: The G40 fires the 10mm cartridge, sports a six-inch barrel for maximum velocity, and features a “no-gunsmithing” mounting system for a variety of red-dot optics.
The pistol was introduced at the 2015 SHOT Show as part of Glock’s line of “red-dot ready” Modular Optic System (MOS) pistols. The MOS pistols feature a milled out area on the slide, in front of the rear sight, where a red-dot optic can be installed. A set of four mounting plates allows the user to pick from the most popular red-dot choices. The milled area is covered by a protective cover when not in use. The other pistols in the MOS lineup are the 9mm G34, the .40 G35, and the .45 ACP G41. All the MOS pistols are Gen 4 designs with improved texturing, adjustable backstraps, and dual captive recoil spring technology.
Even among the Gen 4 MOS pistols the Glock 40 stands out. While the other pistols are designed for competition the Glock 40 is a handgun hunter’s dream. The six-inch barrel is the longest in the Glock stable (tied only the Glock 17L competition model) and the 10mm chambering provides a power level roughly equivalent to the .41 Magnum.
When I opened the box the first thing I noticed was the pistol’s size. With the 6.02” barrel, an overall length of 9.49” and an empty weight of 29.15 ounces the Glock 40 is more suited to an open-carry field holster than a concealed-carry rig. Add a loaded 15-round magazine and the listed weight jumps to 40.14 ounces. (Of course, in practice, the exact weight will depend on the projectiles picked.)
I have reasonably large hands with long fingers and I still found the pistol to be a handful, even with the factory installed small backstrap. The four other backstraps include one with an especially large beavertail which seems suitable for Bigfoot.
The rear sight is adjustable for windage and elevation and the proper sized screwdriver is included in the box. The complete rear sight assembly can also be drifted in the dovetail. The front sight is the normal Glock pinned sight with white dot. Both the front and rear sights are standard height.
The unique proposition for this pistol is the Modular Optic System. This is Glock’s attempt to serve those shooters who want to install a red-dot optic but who don’t want to go to the expensive of having the slide custom-milled. The Glock 40 uses Adapter Plate Set 02 which is specified for pistols with a slide width of 28.5mm (1.12”). The adapter marked “5” is for the Docter, Meopta, and Insight optics, the adapter marked “6” is for the Trijicon RMR, the adapter marked “7” is for the C-More, and the adapter marked “8” is for the Leupold Delta Point.
For this review I borrowed a Trijicon RMR with 1 MOA dot from Trijicon. I wanted to see if the adapter system was as easy to use as promised and then test the pistol with the dot installed. The directions were easy enough: First clear and field strip the pistol so the slide can be placed on a flat work surface. Then use the included hex key to remove the protective cover, position the correct adapter plate in the milled out area with the markings facing upwards, tighten down two of the provided screws to secure the plate to the slide, position the sight so the holes for the mount line up with the holes in the plate and install using the mounting screws provided by the sight manufacturer. (Glock provides two spare screws to attach the plate to the slide but warns not to use them to mount the optic).
This is where things got ugly. The factory Trijicon screws were too long and pushed the optic and adapter plate away from the slide when screwed down. I tried backing them off only to have the optic wiggle like a loose tooth. I went against Glock’s advice and tried the spare adapter plate screws but they were too short. There was no way to make this work with the parts provided.
The problem is that the Trijicon screws were designed to work with their standard rifle mount and the Glock adapter plate simply wasn’t thick enough to allow the screws to fully seat. Although it wasn’t technically their problem Trijicon responded to customer complaints by developing their own adapter plate for the Glock 40 that works with their standard length mounting screws. When I contacted Trijicon they promised to get one to me as soon as possible.
In the meantime I still had to test the pistol. Rather than stick solely to the iron sights I contacted various industrial fastener suppliers in my area and finally found one who could provide me with a set of screws with the proper thread and length (no hardware store had them). The difference was the substitute screws were carbon steel, instead of stainless, and lacked the black protective coating of the Trijicon screws. Once I had the screws in-hand installation was as easy as promised. Although the instructions didn’t mention it, I noticed a small amount of blue thread-locker on the Trijicon supplied screws so I added a dab of blue Loc-tite to the mounting screws before installation.
Although I was a little concerned about my substitution there were no problems at the range. The Trijicon RMR remained rock-solid on the slide and the screws showed no evidence of backing out or shearing.
I tested the pistol with variety of 10mm ammunition from Hornady and DoubleTap Ammunition. The Hornady loads were their 155 gr and 180 gr XTP JHP offerings while DoubleTap provided me with selections from their target, tactical, and hunting lines. Accuracy testing was at 20 yards, instead of the standard 25 yards, because the pistol bay I used was already set up at the shorter distance and I was unable to move the bench unassisted.
The bench testing quickly proved that the combination of the Glock with the Trijicon RMR was capable of more accuracy than I had the skill to deliver. It was ridiculously easy to position the 1 MOA dot in the exact center of the bullseye targets. By only having to focus on one sighting plane many of the problems caused by my poor vision were eliminated. The only inconsistencies were shooter induced as I worked to improve my trigger control with the pistol’s standard 5.5 pound trigger. The single best group was with the Hornady 180 gr XTP load with four shots touching in ¾ of an inch with a fifth flyer opening the group up to 1 ½”. That group printed about an inch below the target center. The second best group was with the DoubleTap Target DT 180 gr FMJ load with four shots in the 10-ring at just about 2” with the fifth flyer opening the total group up to 3”. That group was more centered on the bull with the flyer edging into the 9 ring. The reminder of the accuracy testing typically had “four and one” results with one flyer opening up the overall group to 3” or 4” inches.
In addition to accuracy testing I worked with paper and steel targets to get a feel for the pistol with a variety of bullet weights. The heavy six-inch barrel shifted the balance towards the muzzle which helped make the pistol “hang” on target and improved shot-to-shot recovery. The recoil was noticeable, but controllable, even with the heaviest DoubleTap 230 gr hardcast hunting load. The extra weight and barrel length made the lighter 155 gr and 180 gr Hornady JHP’s feel like shooting .40 S&W or possibly even hot 9mm’s.
What I Like
This is a kick-ass hunting pistol, plain and simple. The red dot optic will allow for fast target acquisition on game while the long barrel will get the most out of the 10mm loading. It seems suitable for most North American animals aside from the extremes of moose (too big) and squirrel (too small.) The ability to place multiple quick shots on a fast target make it ideal for feral hog hunting.
What I Didn’t Like
While the Modular Optic System is touted as the “easy way” to mount a red-dot optic, in practice it involved a lot of frustration. I was only able to try out the Trijicon RMR and don’t know if any of the other optics and mounting plates would have similar issues. Still, I was able to overcome the issue and Trijicon even got one of their adapter plates out to me after my range test, so that problem is on its way to being resolved.
The only other disappointment was that the standard height sights do not allow co-witness when the optic is installed. I’m surprised Glock didn’t use taller “suppressor sights” instead. Those are easy enough to install though for anyone who wants back-up capability.
If you’ve read this far you’re likely in the Venn diagram of “Shooters who want a 10mm pistol,” “Handgun hunters” and “Shooters who want a handgun mounted red-dot optic.” If that’s you, you know you want one, and I do too.
Glock 40 Gen 4 MOS
Caliber: 10mm Auto
Barrel Length: 6.02”
Mag Capacity: 15 rounds
Trigger Pull: 5.5 pounds