Glock MOS Opinions

Tallest · April 29, 2019, 09:15 AM

Good morning, Folks,

I've been looking into having one of G17s or G19s milled for an RMR, or perhaps purchasing an Gen 5 MOS model of one or the other. Or maybe... just maybe... I'll spring for a G40 for the sheer fun of it!

But this past weekend, during the NRA convention, Glock announced the G45 MOS, and it seemed that the better part of the feedback was negative. Of course some folks were just mad that their dream Glock still isn't a reality, but there seems to be a lot of specific dissatisfaction with the MOS setup as it keeps the optic of choice too high and sometimes doesn't allow for a secure enough mounting (people stated their optics had flown off).

So any of you out there that have a Glock MOS model, I'd be interested in some objective feedback. I appreciate it!

Tactical Jackalope · April 29, 2019, 10:18 AM

I have a Gen 5 Glock 34 MOS.

I have heard the same thing about the MOS needing to be redrilled in order to support an RMR or any other optic more securely.

Trijicon has actually made mounting plates with better screws for the MOS models and it fully fixes said issue.

Sharkbite · April 29, 2019, 10:28 AM

I had (past tense)

a G19MOS. After i broke the second mounting plate during training, i had another 19 milled for my RMR’s and sold the MOS.

The issues i saw were this...

1. The ultra short screw bite into the plate. The screws go thru the RMR and then into just the plate (not thru the plate into the slide). This means the screws holding your optic only get about 3/4 of a turn (bite) into the plate

There are separate screws that hold he plate to the slide.

2. The two plates that broke, snapped in half between the screw holes. Obviously a week point.

I would NEVER use a MOS Glock for serious use. As a strict range toy MAYBE... but i would expect it to break at some point.

The G19 that i had milled has the screws going thru the RMR and directly into the slide. Solid system.

Tallest · April 29, 2019, 10:34 AM

Quote:

Originally Posted by Tactical Jackalope

I have a Gen 5 Glock 34 MOS.

I have heard the same thing about the MOS needing to be redrilled in order to support an RMR or any other optic more securely.

Trijicon has actually made mounting plates with better screws for the MOS models and it fully fixes said issue.

Do you feel like the RMR sits too high with that setup?

DaleA · April 29, 2019, 02:43 PM

A Glock in 10mm has been on my mind for quite a while and one of the things contributing to my analysis paralysis was the "standard" G20 or go for the G 40 long slide (6 inch barrel vs the G20 with the 4.6 inch barrel) and the G40 has the Modular Optic System (MOS). Seems like it might be better to go whole hog and get the G40.

Discussions like this are one of the really nice things about this site. I'm constantly amazed at the wealth of information, the willingness to share and the overall politeness on this site. There are a lot of folk that appreciate this even if we don't post each and every time we luck into a discussion that affects us.

TCphoto · April 30, 2019, 09:37 AM

I found a great deal on a lightly used G17.5 MOS and am waiting on delivery. I like that there is no cutout, Ameriglo sights but am neutral on the front serrations. The previous owner says it's had less than 100 rounds through it, so it's nearly unused. I don't intend on installing optics but it's good to know that it's ready should I chose to do so.

precision_shooter · April 30, 2019, 11:37 AM

I have both the G20 and I recently bought a G40 MOS.

I like both for different reasons.
G20 is just a great gun and 10mm is great for defense from both 2 or 4 legged critters.

The G40 I have has the Vortex Venom sight. The screws seem to have much more purchase to the plate than 3/4 of a turn mentioned above about the RMR sight. Although I haven’t shot it much, I sure do like it for the fast target acquisition it provides. I would never rely on any electronic sight as my main means of sights for a defense weapon so it does not get that role.

No issues as of yet with the mount or sight and hope it stays that way.

I see no point for the sight on a G19/G45 size pistol so have no interest in getting anything that size to mount a red dot optic to. G34 is the smallest I could see me having a sight on.

Unable to get pics/files to upload atm.

labhound · May 1, 2019, 12:55 AM

I shoot a gen 4 G19 MOS with a Burris Fastfire III in IDPA matches. Excellent combination for competitions. Red dots have two weaknesses, the batteries and the screws holding them onto the slides. Batteries get weak and the red dots fail at the most inconvenient times. The sights take a pounding and even though the screws holding them on have loctite on them, they can come loose and even fall off. I had this happen to me during a tier 2 IDPA match. I wouldn't depend on a pistol with a red dot for defensive use, but for competitions they're hard to beat.

DaleA · May 1, 2019, 08:09 AM

Thanks for the insight precision_shooter. Now even more stuff to think about.

Ruger45LC · May 1, 2019, 09:09 PM

The only MOS model I've owned is the G40, I've had two of them. They're cool, although I personally never used the MOS feature, but if you really wanted to use an optic then I'd say they would be very good. The G40 is nice, it's a bit big but in general I prefer the G20 overall.

Jeff22 · May 7, 2019, 02:01 AM

I have a couple of friends who recently got various Glock MOS pistols.

One has a Trijicon RMR and all the others (I think) have various RDS from Vortex. (Vortex is a local vendor and I have a bunch of acquaintances that work there. They have a great warranty but as of yet is seems their products are not yet as durable as Trijicon or Aimpoint if you run them hard. I will be interested to see their experiences as time goes on.

I have a Glock 34 with the slide cut and I have an RMR 06 series 2 on that, and I have about 2000 rounds through it. If I get another gun and put an RDS on it (which is likely) I'll probably get the slide cut on that one too -- results in a stronger mount but it does limit what kind of optic you can use.

Tallest · May 7, 2019, 08:58 AM

Quote:

Originally Posted by Jeff22

I have a couple of friends who recently got various Glock MOS pistols.

One has a Trijicon RMR and all the others (I think) have various RDS from Vortex. (Vortex is a local vendor and I have a bunch of acquaintances that work there. They have a great warranty but as of yet is seems their products are not yet as durable as Trijicon or Aimpoint if you run them hard. I will be interested to see their experiences as time goes on.

I have a Glock 34 with the slide cut and I have an RMR 06 series 2 on that, and I have about 2000 rounds through it. If I get another gun and put an RDS on it (which is likely) I'll probably get the slide cut on that one too -- results in a stronger mount but it does limit what kind of optic you can use.

I think that's the direction I'm starting to lean. Thanks!

precision_shooter · May 7, 2019, 01:30 PM

Trijicon is a good sight, and I compared it to the vortex side by side then bought the vortex. Trijicon has to be removed from the gun to change a battery. Vortex has a top load battery compartment so don’t have to remove the sight to change battery. I know the batteries last for a long time. But having to re-sight it every time you change the battery was unappealing to me and the vortex (with lifetime warranty) was half the cost of the Trijicon.

April 29, 2019, 09:15 AM	#1
Tallest Senior Member Join Date: January 23, 2016 Location: West of the Atlantic Posts: 418	Glock MOS Opinions Good morning, Folks, I've been looking into having one of G17s or G19s milled for an RMR, or perhaps purchasing an Gen 5 MOS model of one or the other. Or maybe... just maybe... I'll spring for a G40 for the sheer fun of it! But this past weekend, during the NRA convention, Glock announced the G45 MOS, and it seemed that the better part of the feedback was negative. Of course some folks were just mad that their dream Glock still isn't a reality, but there seems to be a lot of specific dissatisfaction with the MOS setup as it keeps the optic of choice too high and sometimes doesn't allow for a secure enough mounting (people stated their optics had flown off). So any of you out there that have a Glock MOS model, I'd be interested in some objective feedback. I appreciate it! __________________ Matthew "All men are ignorant. The topics of our ignorance may vary, but the nature of the world is that no man may know everything." ~ R Jordan

April 30, 2019, 11:37 AM	#7
precision_shooter Senior Member Join Date: September 8, 2007 Location: DFW, Texas Posts: 2,475	I have both the G20 and I recently bought a G40 MOS. I like both for different reasons. G20 is just a great gun and 10mm is great for defense from both 2 or 4 legged critters. The G40 I have has the Vortex Venom sight. The screws seem to have much more purchase to the plate than 3/4 of a turn mentioned above about the RMR sight. Although I haven’t shot it much, I sure do like it for the fast target acquisition it provides. I would never rely on any electronic sight as my main means of sights for a defense weapon so it does not get that role. No issues as of yet with the mount or sight and hope it stays that way. I see no point for the sight on a G19/G45 size pistol so have no interest in getting anything that size to mount a red dot optic to. G34 is the smallest I could see me having a sight on. Unable to get pics/files to upload atm. __________________ "Laws that forbid the carrying of arms...disarm only those who are neither inclined nor determined to commit crimes...Such laws make things worse for the assaulted and better for the assailants; they serve rather to encourage than to prevent homicides, for an unarmed man may be attacked with greater confidence than an armed man." - Thomas Jefferson, 1776 Last edited by precision_shooter; May 1, 2019 at 07:23 AM.

May 7, 2019, 02:01 AM	#11
Jeff22 Senior Member Join Date: September 15, 2004 Location: Madison, Wisconsin Posts: 715	I have a couple of friends who recently got various Glock MOS pistols. One has a Trijicon RMR and all the others (I think) have various RDS from Vortex. (Vortex is a local vendor and I have a bunch of acquaintances that work there. They have a great warranty but as of yet is seems their products are not yet as durable as Trijicon or Aimpoint if you run them hard. I will be interested to see their experiences as time goes on. I have a Glock 34 with the slide cut and I have an RMR 06 series 2 on that, and I have about 2000 rounds through it. If I get another gun and put an RDS on it (which is likely) I'll probably get the slide cut on that one too -- results in a stronger mount but it does limit what kind of optic you can use. __________________ You can only learn from experience if you pay attention!

May 7, 2019, 01:30 PM	#13
precision_shooter Senior Member Join Date: September 8, 2007 Location: DFW, Texas Posts: 2,475	Trijicon is a good sight, and I compared it to the vortex side by side then bought the vortex. Trijicon has to be removed from the gun to change a battery. Vortex has a top load battery compartment so don’t have to remove the sight to change battery. I know the batteries last for a long time. But having to re-sight it every time you change the battery was unappealing to me and the vortex (with lifetime warranty) was half the cost of the Trijicon. __________________ "Laws that forbid the carrying of arms...disarm only those who are neither inclined nor determined to commit crimes...Such laws make things worse for the assaulted and better for the assailants; they serve rather to encourage than to prevent homicides, for an unarmed man may be attacked with greater confidence than an armed man." - Thomas Jefferson, 1776

April 29, 2019, 10:18 AM	#2
Tactical Jackalope Senior Member Join Date: December 5, 2010 Location: Miami, Florida Posts: 6,429	I have a Gen 5 Glock 34 MOS. I have heard the same thing about the MOS needing to be redrilled in order to support an RMR or any other optic more securely. Trijicon has actually made mounting plates with better screws for the MOS models and it fully fixes said issue.

April 29, 2019, 10:28 AM	#3
Sharkbite Senior Member Join Date: November 4, 2013 Location: Western slope of Colorado Posts: 3,679	I had (past tense) a G19MOS. After i broke the second mounting plate during training, i had another 19 milled for my RMR’s and sold the MOS. The issues i saw were this... 1. The ultra short screw bite into the plate. The screws go thru the RMR and then into just the plate (not thru the plate into the slide). This means the screws holding your optic only get about 3/4 of a turn (bite) into the plate There are separate screws that hold he plate to the slide. 2. The two plates that broke, snapped in half between the screw holes. Obviously a week point. I would NEVER use a MOS Glock for serious use. As a strict range toy MAYBE... but i would expect it to break at some point. The G19 that i had milled has the screws going thru the RMR and directly into the slide. Solid system.

April 29, 2019, 02:43 PM	#5
DaleA Senior Member Join Date: September 12, 2002 Location: Twin Cities, MN Posts: 5,313	A Glock in 10mm has been on my mind for quite a while and one of the things contributing to my analysis paralysis was the "standard" G20 or go for the G 40 long slide (6 inch barrel vs the G20 with the 4.6 inch barrel) and the G40 has the Modular Optic System (MOS). Seems like it might be better to go whole hog and get the G40. Discussions like this are one of the really nice things about this site. I'm constantly amazed at the wealth of information, the willingness to share and the overall politeness on this site. There are a lot of folk that appreciate this even if we don't post each and every time we luck into a discussion that affects us.

April 30, 2019, 09:37 AM	#6
TCphoto Junior Member Join Date: February 11, 2019 Location: Madison, GA Posts: 8	I found a great deal on a lightly used G17.5 MOS and am waiting on delivery. I like that there is no cutout, Ameriglo sights but am neutral on the front serrations. The previous owner says it's had less than 100 rounds through it, so it's nearly unused. I don't intend on installing optics but it's good to know that it's ready should I chose to do so.

May 1, 2019, 12:55 AM	#8
labhound Senior Member Join Date: August 24, 2010 Posts: 363	I shoot a gen 4 G19 MOS with a Burris Fastfire III in IDPA matches. Excellent combination for competitions. Red dots have two weaknesses, the batteries and the screws holding them onto the slides. Batteries get weak and the red dots fail at the most inconvenient times. The sights take a pounding and even though the screws holding them on have loctite on them, they can come loose and even fall off. I had this happen to me during a tier 2 IDPA match. I wouldn't depend on a pistol with a red dot for defensive use, but for competitions they're hard to beat.

May 1, 2019, 08:09 AM	#9
DaleA Senior Member Join Date: September 12, 2002 Location: Twin Cities, MN Posts: 5,313	Thanks for the insight precision_shooter. Now even more stuff to think about.

May 1, 2019, 09:09 PM	#10
Ruger45LC Senior Member Join Date: July 24, 2005 Location: Kentucky Posts: 768	The only MOS model I've owned is the G40, I've had two of them. They're cool, although I personally never used the MOS feature, but if you really wanted to use an optic then I'd say they would be very good. The G40 is nice, it's a bit big but in general I prefer the G20 overall.