Factory Glock Gen 3 Slide Cut for MOS plates?

I am excited for the Acro P2 as finally crossing the threshold of technology advancements where I'll buy my first red dot pistol. :)

I have my reasons, which wont make sense to most and admittently are stupid but I'd like to get a Glock Gen 3 slide and have it milled for MOS plates. I typed them out but deleted them because they'll side track the conversation and everyone will call me stupid. I have some niche reasons that don't apply to most.

Regarding an MOS plate cut, I don't need or want a direct cut, because I'd like to future proof things. I don't plan to CCW this gun, it will be for a Safariland holster on a war belt rig. So the added benefits of direct mill don't outweigh the cost of needing to get a new slide cut every 5 to 10 years as I get a new red dot. I suspect the MOS plate system will be an industry standard for at least the next 10 to 20 years, for better or worse. And I'm willing to accept a marginally worse product if it means in 12 years, I can buy the newest red dot and install it on my existing slide with handtools in a few minutes.

Given my desires, could I have a Gen 3 slide cut for MOS plates? What downsides exist? Other than:

Gen 5 is a more accurate better system than Gen 3.
MOS plates are not amazing compared to other plates
Direct Mill allows a more streamlined overall package for CCW

I'm aware of those downsides and the benefits of sticking with Gen 3 outweigh the costs for me personally.

Since it may pique people's interests, I'll give just one of my very niche reasons for this decision. I have standardized on M13.5X1 LH as a silencer pitch because my Gen 3 Glock Factory barrels all run that pitch. The Gen 5 barrels run 1/2x28 and I don't want to deal with swapping pistons in my silencer depending on the gun I use. I don't come close to the mechanical accuracy of my Gen 3 Glock because I'm not an amazing shooter, I shoot mediocre ammo that's cheap, and I don't compete so the Gen 5 benefits do not outweigh the silencer piston switching cost.

Sounds like it’s what you really want. Kyle Defoor had a Gen4 milled for MOS btw.

I don't think this can be done successfully and still keep the stock rear sight dovetail.

Glock moved the rear sight dovetail cut on the MOS models farther to the rear than on the non-MOS models, and I think they had to do that to make room for the MOS plate cut (it is very close to the extractor cut), or to get a better (more solid) location for the mounting holes. If they could have made the cut and added the MOS plate without moving the rear sight, I believe they would have done so. The fact that they moved it, means there was probably a very good reason for moving it.

Now, if you don't care about keeping the existing rear sight or rear sight dovetail, then it might be doable.

An aftermarket Modular slide from Unity or Agency would be a better option if you are stuck with gen 3 like CA.

Or just get a KKM barrel with the threading you want.

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Originally Posted by HCM

Now, if you don't care about keeping the existing rear sight or rear sight dovetail, then it might be doable.

An aftermarket Modular slide from Unity or Agency would be a better option if you are stuck with gen 3 like CA.

Or just get a KKM barrel with the threading you want.

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Great info, thank you so much for this. I think I'd like to keep the rear sight. It seems really useful, but I don't have any experience on a red dot handgun yet.

I went on KKMs site and they only seem to sell 1/2x28 threaded barrels, so unless they can custom thread me one, I don't think it's an option.

I may just forgo having matching barrel threads and if I want to share my single suppressor across multiple Glocks, I have to change the piston. Not a huge deal I guess, I do have the pistons and the wrench. And if I want to put the silencer on a subgun, I need to change the piston and add the fixed spacer thing anyway. I don't really need to swap silencers onto different glocks quickly. Even in my wildest LARPing fantasies I struggle to think of a scenario where I dont have a few minutes to change the piston.

The other main reason I wanted to avoid Gen 5 is I already have a ton of spare Gen 3 Glock parts stockpiled away for a rainy day. Enough to build 2 new Gen 3 Glocks. I like having spare parts and if I have to go Gen 5, then I will need to buy a few of the parts that dont interchange to keep on hand. Not the end of the world I guess.

Otherwise my option is to get a Unity or Agency Gen 3 slide, which then locks me into their proprietary system that I doubt will last 20 to 30 years. The Glock MOS might not even last 20 to 30 years but it's almost guaranteed to last longer than any third party proprietary mounting system. Also, the Unity Gen 3 is out of production.

I looked up Agency Arms, and it's $1100 (yikes) for a stripped slide Gen 3 Glock that takes AOS plates. Plus $140 for the Acro plate. I could use my Gen 3 threaded factory M13x1 LH barrels though.

But for that price, and the fact that I don't trust the AOS plates to be available for as long as MOS plates, I think I'd rather just buy a new Gen 5 Glock plus some spare parts, and deal with having to change the piston. For about half the price, and get a whole new gun, that people say is vastly better than Gen 3. I talked myself out of sticking with Gen 3 based on HCMs knowledge.

If someone puts forth a solid argument that AOS plates will be available for new optics for longer than the MOS system, then I would drop the $1100 on the Gen 3 Agency slide and go that route, to not have to deal with this again in 10 years. I really hate buying new accessories for my guns. I have limited time to spend on guns and dont live fire or dryfire enough as-is. This research right now is actively taking me away from dryfiring tonight.

What I'd like to do is get this one red dot sight handgun, and in 5 to 10 years see what new better dot tech exists, and just get a new plate for it and buy that new optic. And do the same in 10 to 15 years on the same slide. Not have to deal with "now I have to buy the new Gen 7 Glock to get a gun that has a plate that fits with the Acro P4, but the Gen 7 Glock means a new threaded barrel, new holster, new spare parts, and a New X, Y, Z to go along with it"

I plan to live about 30 to 40 more years max and if I could squeeze out a red dot Glock now in 2021 that will last until I die, with simple optics and plate changes every 5 to 10 years, that would make me very happy. And let me dedicate more time to training. Eventually, advances will become marginal anyway. The difference between a 2010 handgun red dot and a 2015-era one are huge. 2015 and 2020 a little less so. And I expect maybe the optic I buy in 2030 or 2035 can last until 2050 with just battery changes, as long as it doesn't break. So if I can get 10 to 15 years out of a plate system, I think that may be enough.

Maybe there's a different angle to think about this from. What's the most common pistol RDS footprint? My perception is it's the RMR. It's been evolving and going strong for what, ~12-13yrs I think? Think about the industry support that's grown around that one platform. That's not going to disappear overnight, that is unless Trijicon wants to become irrelevant just when the pistol RDS renaissance has started to go mainstream.

I suspect as competitive pressure grows, they won't throw away that progress and will eventually continue innovating within the RMR footprint. Holosun has already been eating their lunch for several years on Trijicon's own footprint! ;) Obviously the ACRO and that style of railed mounting system (509T for example) is probably going to be the way of the future because it just makes sense. I would guess at some point the industry will start to standardize on a pistol RDS rail spec somewhat akin to a shrunken 1913 rail, but I digress.

Adapter plates for RMR cuts seem like a desirable compromise. For example, here's a few for the ACRO from Primary Machine, Aimpoint, and KE Arms. The MOS system is only Glock. RMR cuts span many different brands. Also, adapter plates for a common footprint seem like a fairly simple component to manufacture which is nice from a future-proofing standpoint. Flat plate with a couple beveled screw holes, maybe a couple divots on the underside for recoil lugs, then whatever footprint mounting system on top.

Quote:

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Originally Posted by Sanch

Great info, thank you so much for this. I think I'd like to keep the rear sight. It seems really useful, but I don't have any experience on a red dot handgun yet.

I went on KKMs site and they only seem to sell 1/2x28 threaded barrels, so unless they can custom thread me one, I don't think it's an option.

I may just forgo having matching barrel threads and if I want to share my single suppressor across multiple Glocks, I have to change the piston. Not a huge deal I guess, I do have the pistons and the wrench. And if I want to put the silencer on a subgun, I need to change the piston and add the fixed spacer thing anyway. I don't really need to swap silencers onto different glocks quickly. Even in my wildest LARPing fantasies I struggle to think of a scenario where I dont have a few minutes to change the piston.

The other main reason I wanted to avoid Gen 5 is I already have a ton of spare Gen 3 Glock parts stockpiled away for a rainy day. Enough to build 2 new Gen 3 Glocks. I like having spare parts and if I have to go Gen 5, then I will need to buy a few of the parts that dont interchange to keep on hand. Not the end of the world I guess.

Otherwise my option is to get a Unity or Agency Gen 3 slide, which then locks me into their proprietary system that I doubt will last 20 to 30 years. The Glock MOS might not even last 20 to 30 years but it's almost guaranteed to last longer than any third party proprietary mounting system. Also, the Unity Gen 3 is out of production.

I looked up Agency Arms, and it's $1100 (yikes) for a stripped slide Gen 3 Glock that takes AOS plates. Plus $140 for the Acro plate. I could use my Gen 3 threaded factory M13x1 LH barrels though.

But for that price, and the fact that I don't trust the AOS plates to be available for as long as MOS plates, I think I'd rather just buy a new Gen 5 Glock plus some spare parts, and deal with having to change the piston. For about half the price, and get a whole new gun, that people say is vastly better than Gen 3. I talked myself out of sticking with Gen 3 based on HCMs knowledge.

If someone puts forth a solid argument that AOS plates will be available for new optics for longer than the MOS system, then I would drop the $1100 on the Gen 3 Agency slide and go that route, to not have to deal with this again in 10 years. I really hate buying new accessories for my guns. I have limited time to spend on guns and dont live fire or dryfire enough as-is. This research right now is actively taking me away from dryfiring tonight.

What I'd like to do is get this one red dot sight handgun, and in 5 to 10 years see what new better dot tech exists, and just get a new plate for it and buy that new optic. And do the same in 10 to 15 years on the same slide. Not have to deal with "now I have to buy the new Gen 7 Glock to get a gun that has a plate that fits with the Acro P4, but the Gen 7 Glock means a new threaded barrel, new holster, new spare parts, and a New X, Y, Z to go along with it"

I plan to live about 30 to 40 more years max and if I could squeeze out a red dot Glock now in 2021 that will last until I die, with simple optics and plate changes every 5 to 10 years, that would make me very happy. And let me dedicate more time to training. Eventually, advances will become marginal anyway. The difference between a 2010 handgun red dot and a 2015-era one are huge. 2015 and 2020 a little less so. And I expect maybe the optic I buy in 2030 or 2035 can last until 2050 with just battery changes, as long as it doesn't break. So if I can get 10 to 15 years out of a plate system, I think that may be enough.

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Call KKM. They are very capable.

Handguns are consumable / disposable items. If you shoot them in volume they wear out, if you need to use one for real it’s either going into evidence or down a storm drain. Either way nothing is forever.