The Glock 17 has become an icon ever since it was first developed in the early 1980’s. A lot of things have changed in the past 40 years, but the overall design of the Glock is not one of them.
If you were to compare an original Glock 17 and the current Generation Glock 17 side by side, there would only be subtle cues as to the things that have been changed.
That is not to say nothing has changed, several things have actually.
Things such as Glock’s added a railed dust cover under the barrel. Glock has also added finger grooves to the grip, and subsequently removed said grooves in the most current iteration.
Grip texture has also been changed over the years.
Glock went from a very slick texture to one that quite literally will wear/tear holes in your garments if you aren’t careful or mindful.
Glock has since dialed their texture game back a notch and have found a happy medium.
Glock 17 MOS Features
The Glock 17 is feature packed and one of the most popular 9mm pistols in the world.
The grip of the Gen 4 Glock 17 is nothing special. Usually when you say those words, it isn’t good, but here I would argue that it actually is.
Glock has found what I believe to be the perfect sweet spot between a slick piece of polymer and a texture that can remove layers of skin if you rub your hand against it a little too hard.
As Glocks have grown in popularity, people have taken to sanding down the factory texture and then stippling the polymer frame with a soldering iron, or in growing popularity, using a laser to engrave a new texture and or design of their choice.
This customization makes for some interesting grip textures, and the only limit seems to be one’s imagination and wallet.
Ergos on a Glock are pretty much non-existent. It’s a Glock. For most people they feel like holding onto a brick.
I find that in the world of pistols their design is unique, and the feel they give me as a shooter is equally as unique. If I am shooting one of my several other handguns and then immediately switch to one of my several Glocks, the feel of the gun in my hand is noticeably different.
Sometimes I will even find my wrist will cant the Glock up more than say a Sig.
This is due to the grip angle that Glock employs on all their offerings.
As stated above, Glock uses the same grip angle on all of their handguns. While they differ from other brands, the continuity that this feature brings to the table lends to familiarity when going from Glock to Glock.
The grip of the Glock Gen4 MOS sports the somewhat controversial finger grooves.
Having averaged sized hands finger grooves on Glocks and other pistols in general never really bothered me, so I could take or leave them as they are.
The stippling is nice and is also found on the finger groove sections in the low spots where the pads of the fingers rest.
Glock provides dimples for your thumbs on either side of the top of the grip. I find this helpful to rest the strong hand thumb in the dimple and it aids me in sight alignment and bore placement.
The folks at Glock have also provided the end use with a slight undercut to the trigger guard. While in no way does this compare to a custom job, it does a decent job of letting the shooter’s hand ride just a little bit higher on the grip.
This aids in recoil control and gives the shooter more control over the weapon.
While the past few decades have been geared toward replacing the cheap plastic sights often found on stock Glocks, there is little to no need to upgrade them on the Gen 4 MOS, as long as you have an optic installed.
Some would argue that even though you have an optic installed, you should still have a set of sights on a pistol, I find that to be a decision made from preference not necessity.
If you do choose to have a set of iron sights installed, there are several different options to choose from.
The list is much narrower than that of a non MOS Glock, if you want the sights to be usable with the optic installed that is.
The list is narrowed to “suppressor height” sights. This is because the body of the installed red dot, whichever it may be, will obstruct the proper sight alignment of regular height sights.
You will be able to see the rear sight, but you will not be able to line up the front and rear sights for a proper sight picture because of the red dot.
Suppressor height sights will mostly overcome this issue.
Depending on application and use of the firearm, this may dictate your decision as it pertains to aftermarket sights.
For a gun that is used on the range to punch paper, I dont think i would spend the extra money to purchase suppressor height sights to go along with my red dot installed MOS.
If the MOS was used in a self defensive or duty capacity, then I would highly encourage the purchase and use of iron sights in conjunction with the red dot on the Glock MOS.
MOS stands for Modular Optic System.
This is Glock’s (late) answer to the thousands of people that sent their stock slides off to a machine shop to be milled and tapped for a red dot.
Like with most things, Glock seemed to drag their feet when it came to advancing their design to accommodate the booming trend of mounting red dots to their pistols.
I remember nearly a decade ago flipping through gun mags at the grocery store and seeing big, bulky red dots mounted to pic rails that were then in turn mounted to the dust cover.
These guns seemed bulky and unwieldy with the addition of all the material to accomplish the task of adding a red dot to the pistol.
As technology often does, thighs got smaller and smaller until they were small and light enough that the red dots could be mounted to the slide of a pistol and not interfere with the proper function of the firearm.
The location that was chosen to be used for the MOS is the typical location for modern red dot placement. The MOS cut is located between the rear sight dovetail and the back of the lockup if the barrel hood with the slide.
The magazines provided with the Glock 17 Gen 4 are the typical Gen4 mags.
They hold the standard capacity of 17 rounds. Extended mags can also be had that would boost the overall round count up.
You can also obtain mag extensions that will further add to the round count.
There are also non OEM magazines available, the most popular of those would be Magpul.
The Magpul magazines will also hold the standard 17 round capacity.
The controls of any gun, especially a pistol, will make or break the gun and the controls on the Glock 17 are tried and true.
The magazine release on the Glock MOS is the standard Gen4 affair.
It is small and does not protrude far off the side of the Glock too much.
This affords the shooter a snag free point that should not interfere with the normal command grip on the firearm, but also is large enough to actuate positively.
It is located on the grip of the Glock Gen4 at the rear of the trigger guard.
The magazine catch is reversible, but not truly ambidextrous in the sense that it is either located on the left or right side of the gun in accordance with the owner’s preference and placement.
The slide stops of Glocks are notoriously small. This does not change for the Gen 4 MOS.
The slide stop is located in its traditional position on the left side of the gun directly above the magazine release.
The placement of the magazine release and slide stop are such that they can both be manipulated with the right thumb of most adults.
They are also able to both be manipulated with the support hand thumb if that is more comfortable for the shooter.
The Glock factory trigger is what you will find installed on the G17 MOS Gen 4.
The trigger comes standard with the Glock Safe Action that requires the center portion to be depressed before the rest of the trigger is allowed to be pressed.
The trigger pull is nothing special, and is quite typical for a “duty firearm”.
It breaks relatively clean at around 5 to 5.5 pounds. This is a decent weight, and helps to ensure that the trigger pull is an intentional one.
The face of the trigger on the G17 MOS is the smooth style. Some prefer this type, while others prefer the ridged trigger that Glock tends to offer on other models.
Swapping out the trigger shoe is a relatively simple matter should you want to install something completely different.
What can I say; there’s not a whole lot to talk about in the realm of styling for any Glock.
This MOS however does get some styling points for having a FDE, or flat dark earth colored frame instead of the plain black one that you see mostly.
The flat dark earth color used is slightly different from what we’ve come to expect from companies such as Magpul and other manufacturers.
I personally like the shading that this Glock 17 MOS has.
It should be noted that this FDE is actually colored polymer, and not a spray on cerakote or other enamel that some third party companies or distributors add.
If you want to have the slide coated to match, you will need to hand select the color based on visual inspection, not on just the name of the color.
As with other handguns that have red dots added to them, the Glock 17 MOS can also be customized to your preference of red dot, giving it a style unique to the shooter / outfitter.
Accessories for Glocks and guns in general have grown over the years.
We will explore some of the more popular options that people like to pair with their defensive handguns listed below.
MOS Mounting Plate & alternatives
To solve the issue of having people sending off their slides to have them milled, Glock came out with the MOS system. This system allows an individual to place a red dot on their Glock if they so choose, or not to if that is their preference. It also allows the end user to have the modularity to switch to different optics that have a different attachment footprint by simply pairing the correct MOS mounting plate with the desired optic.
This essentially allows you to play musical chairs with your red dot on your pistol where as before once you had the slide milled to fit a dot, you were pigeonholed into using the optics who only shared that particular footprint.
The world of optics has exploded in recent years. There are selections for every price point, all the way from almost $900.00 for a Trijicon RMR type 2 to the budget minded offerings from Holosun.
If you are in the market for a pistol-mounted optic you can find one that is right for you.
If this were my duty gun, I would probably have a Trijicon RMR Type 2 or one of the newer enclosed type red dots.
The enclosed type dots offer all the benefits of the traditional red dot, but it has a second pane of glass that protects the emitter from getting dirty or wet.
Anyone who has worn a pistol on a duty belt, they know that an open-style red dot is basically a cup when in the holster. It will catch all things including dust, debris and rain.
All that foreign matter will block or obstruct the emitter or cause the glass of the red dot to become occluded and not be able to be used in its most optimal way when the operator needs to take a shot.
On this Glock 17 MOS I currently have the Vortex Venom mounted.
While I would not choose this optic for a duty pistol, it is good for plinking and is on the smaller side of pistol optics.
Lights are one of the more traditional additions found on pistols. I often advocate for the use of an attached light to a duty or defensive pistol, but I also think it is important to also have a handheld light to illuminate your residence so you aren’t potentially aiming your pistol at a family member that got up to use the bathroom or get a midnight snack.
Just like with red dots, there are a myriad of choices that span the gamut when it comes to pistol lights.
I would suggest going with Surefire or Streamlight for a cheaper option without sacrificing quality.
On this pistol, I have a Streamlight TLR-1 HL mounted and I quite like the light output it provides.
Threaded Barrels w/ Suppressors & Compensators
Since this Glock 17 MOS is a range toy for me, I have chosen to replace the factory barrel with a threaded barrel.
The threaded barrel allows me to attach a suppressor to make range trips that much more fun.
I find that while using a suppressor it is very beneficial to have a red dot mounted to the slide as the body of the suppressor occludes the standard iron sights.
As mentioned above, you can install suppressor height sights to raise the sight picture up to or slightly above the body of the suppressor, but the use of a red dot will accomplish the same thing and you will be able to use the red dot for sighting.
Another option for an attachment to a threaded barrel is a compensator.
These devices, traditionally found on rifles, have migrated over pistols as of late.
There has been a boon of popularity in competitive shooting as they assist in keeping the muzzle of the gun flat(er) when firing, which allows for quicker follow up shots.
Glock 17 Ammo
Glocks are one of those guns when it comes to ammo they pretty much go bang with anything.
There’s always an exception but more times than not anything goes. Here are a few good options for your Glock 17 to shoot.
Glock 17 MOS Gen4 Final Thoughts
My final thoughts on the Glock 17 MOS is that it is a quality, duty ready, platform that can be outfitted with any red dot that you choose to accomplish any task set before you.
Glock has an outstanding reputation and it shows in the execution of this pistol.
I would recommend this pistol to anyone looking for a solid pistol to mount a red dot to and who didn’t want to have the slide milled to a specific red dot footprint.
Here are some of the answers to the most frequently asked questions about the Glock 17 MOS.
What does MOS stand for?
MOS stands for Modular Optic System
Are there other options besides the OEM plates?
Yes, there are several aftermarket options available. Some are higher quality parts that Glock offers themselves.
Will a fired casing strike the face of my RDS?
Typically, no. Although there is a chance, if you are experiencing this it may be a good idea to have your pistol looked at by a qualified professional and possibly swap out the ejector.
Does Glock offer the MOS platform on their Gen 3 line up? (California compliant)
No, not at this time. Glock offers the MOS platform on the Gen 4 and Gen 5. If you want an optic on a third gen Glock you will have to have the slide milled to accommodate.
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