Glock 34 MOS - First Impressions

[Palmguy]

I've been interested in an RDS-equipped pistol for some time now, and I finally opened my wallet with the availability of the Glock MOS models. I chose to go with the MOS in order to get some experience with an RDS-equipped pistol before investing the time and money in a custom machined slide. I brought home a G34 a few days ago, and selected the Trijicon RM06 (3.25 MOA adjustable brightness) for mounting. I also installed Ameriglo suppressor height sights (tritium front and rear).

I ran into some trouble when I attempted to install the RMR to the interface plate; the screws included with the RMR are approximately .125" too long. With a couple days delay, I was able to source the correct size screw and installed the RMR today.

I've read some concerns/criticism of the MOS design, particularly at a forum connected with one of the vendors that manufactures a custom RDS-ready slide and performs machining to install red dot sights. I read about one failure already on a G40 (10mm). The slide does get thin at one point above the cutout for the extractor. Also, thread engagement for the RDS mounting screws is somewhat limited due to the design decision by Glock to accomodate multiple makes of sights, necessitating an interface plate instead of a direct mount to the slide. The interface plate is .100" thick, giving about 3 threads engagement in the case of the RMR (not sure what threads the other sights use). The RMR interface plate has two round lugs that interface with the sight. The mounting height of the RMR just allows for the use of the suppressor height iron sights.

I was able to get to the range briefly today perform a functional check and zero; fired 100 rounds Blazer Brass plus a mag's worth of my defense ammo (Gold Dot 124gr +P). I initially adjusted the red dot to coincide with the top of the front sight, and had to make only minor elevation adjustments as POI was just a tad low. I've never fired an RDS equipped pistol before; it was pretty easy to pick up, and I found it easier/quicker to accurately hit at the farthest distance that I was able to shoot at my local indoor range (~50').

From an engineering standpoint, I believe that a slide machined specifically for an RMR (or whatever else) would be better, but I'm happy with the 34 MOS so far. Looking forward to shooting it more and working it in to replace the Gen3 34 that currently serves as my home defense gun.

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[Eurodriver]

Thanks for the review.

I want a G34 w/ RDS with the new SL Threaded barrel, my Octane 9, and a TLR with a 33rd magazine for the ultimate blasting handgun.

I have two questions:

Have you used a T1/H1? I'm guessing yes. If so, which dot do you prefer?
If you had unlimited money and could go back in time, would you still get the MOS or get a Gen4 G34 and have the slide milled?

I ask those because I am really debating the ALG 6 second mount with a T1, a G34 MOS, or a custom milled slide.

[Palmguy]

I don't currently have an Aimpoint Micro (used to though), so I can't directly compare, but the dots seem very similar to me. They're pretty close to the same size, and my perception of both is a little screwed up due to a slight astigmatism.

With the benefit of hindsight and the ability to keep my patience in check, I'd probably go the custom route, but that said, I don't regret my choice at all.

My opinion might change after shooting it, but I didn't want to go with the ALG mount due to the holster changes required.

Forgot to mention...I hesitated on the dot size, a lot of people seem to prefer the larger dots on a pistol. To be honest, I didn't find myself wishing I got the RM07 today.

[teutonicpolymer]

The slide is pretty damn thin between the mounting plate and the extractor

[sidewaysil80]

If you don't mind sharing, what was the price difference between a regular g34 and the MOS version? Also, thank you for posting an unbiased and thorough review.

The slide diameter near extractor makes me a little uneasy. Also, I am skeptical about the the quality of fitment by using the plate system. I am curious how much is saved going this route as opposed to sending the slide off for a custom cut and installation.

[Fishbed77]

Can you post a photo showing how the sights co-witness with the RMR?