Review: UM3 Pistol Sight Mount and Holster

UM3 Pistol Sight Mount

Have you ever wanted to mount a red-dot optic on your pistol but didn’t want to send your slide in to be milled? Well, now you can attach a red-dot with a 1913 rail mount to most pistols with a front attachment rail (a 1913 style front rail or similar), such as most Glock models, various Springfield XD models, many Smith & Wesson M&P models, as well as many others with the UM Tactical, UM3 sight mount.

Getting your slide milled for red-dot style pistol sights will often run you around $200, once you add in shipping, etc., and this does not include an optic. For under $100, you can get UM3 that will clip on, no machining necessary, and try out a red-dot on your pistol. If you’ve never shot a pistol with a red-dot, I suggest you try something like this first, or try out a friends before spending a bunch of money and getting your slide machined.


This installation of the sight mount is pretty simple… you just slide it on the the rail of your pistol until it clicks into place. I tested it out on my Glock 17, and it went on smooth, though it was a tight fit. But this is not something that you want slopping around.

UM3 Pistol Sight Mount - Top View

The rail is split on the top, so it’s easier to install, and once a red-dot is clamped down, it seems to clamp a little tighter on the pistol. This makes the mount quite universal, but still allows it to hold tight.

Once you have the rail on the pistol, you simply attach your red-dot on the 1913 rail on the top. I’m using a Vortex Razor for my testing and it seems to fit and clamp down just fine. The clamping process is a bit of a pain though. Since the rail is split, you generally have to squeeze it together, then place the red-dot on, and start to tighten it up. I’m not a fan of using the red-dot mounting solution as a pair of pliers to compress the rail… But it does work, and nothing has broken with a few on and offs of the optic. So just something to be careful of since you have to tighten things down pretty tight.


As for overall fit, the rail fits OK. Though on my Glock 17, it seems to be a touch off center; thought it’s hard to tell for sure. The mount clamps on the accessory rail pretty tight, and doesn’t seem to wiggle around at all, so that is good.

UM3 Pistol Sight Mount - Front View

Other than that, everything seems to fix and work well.

Here is a list of guns the rail is said to work with:

Smith & Wesson S&W 1911 TA, SD40 VE, M&P .40 M&P 9MM, M&P .357 M&P 45
Sig Sauer 220, P226, P227, P229, P250, SP2022, Mosquito
Walther PPQ PK-380, CCP, PPS
Springfield XD-M, XD, 1911 Operator
Taurus PT92
CZ – USA P-09 Duty, P-07 Duty, P-01, 75 SP-01, 75 SP-01 Tactical, P-09 FDE, Shadow Target, 75 Compact SDP
Beretta PX4 Storm, 92A1, 96A1
Kel Tec PMR-30
Colt .45ACP
GLOCK G41, G38, G37, G35, G34, G32, G31, G30S, G23, G22, G19, G17
FHN USA FNS, FNX, Five-Seven
H&K P30, HK45, P2000
Chiappa 1911-22
Magnum Research Baby Desert Eagle

An updated list is kept, here.


The UM3 is constructed of 6061-T6 aluminum and Type-III hard anodized. So it should be durable, semi-scratch resistant and take a decent beating. The overall build quality is nice, there are no excessively sharp edges or major blemishes, etc.



So now that you have a red-dot mounted on your pistol, it all sighted in and ready to go, how are you going to carry this setup?

Well, UM Tactical also makes a “universal” carbon fiber paddle holster with cutouts for the UM3 mount, the UMH3C.

UM3HC Pistol Holster

The UMH3C holster is a basic adjustable carbon fiber speed holster with no mechanical retention. It’s a universal holster that fits many various pistols, so it’s not really designed to be a run around type of rig, though it seems to be well constructed and pretty durable. Also, my pistol fits pretty darn tight, so there will definitely be some break in time required.

I generally prefer holsters with some level of mechanical retention, but this one definitely works for playing around at the range, or other times when you may not need major retention.

The holster uses a Bladetech adjustable paddle that will work with belts up to 2.5″ wide; a nice added feature.

UM3 Pistol Sight Mount with UM3HC Holster

Into the actual shooting with the red-dot, well, it works like you would expect it too… aim, then shoot. But, there are some gotchas with a setup like this… the primary one being that the sights height over bore is pushing on 2″… So at distance that’s not too big of a deal, but at closer ranges, your point of impact will be low. This type of thing really can come into play when trying to shoot around or over objects. So just something to keep an eye on.

Also, shooting with a red-dot takes a while to get adjusted too. There is less of a point of reference, so if you draw your weapon and don’t see the dot, you end up doing a little jiggling around to find it. It just takes practice to get used to it, and once you get it down, it’s pretty nice.

It took me about 10 rounds to get everything sighted in, and then, everything just works with this. I didn’t take it on and off of the pistol, but the sight stayed accurate between reloads, messing around with targets, holstering, etc.

UM3-Target-1 UM3-Target-2


I got mine from Mounting Solutions Plus (UH3 Mount, UMH3C Holster). Check them out, they generally have a lot of promotions going on.


Ratings (out of 5 stars)

Ease of Installation * * * ½
This is one of the easier accessories you could install on a pistol. The only “gotcha” is actually putting the optic on the 1913 rail because of the split. It requires a little “work,” so I dropped half a star for that.

Build Quality * * * * *
The UM3 Pistol Sight Mount is made out of good material, 6061-T6 aluminum and is Type-III hard anodized. There are no rough edges, and overall it’s a simple design. As far as aluminum accessories go, that is about as good as you can ask for.

Functionality * * * ½
This mounting system works, but I wouldn’t consider it permanent for anything like a competition gun, etc. I look at it more as a tester to see if you like a red-dot on your pistol, or if you want to have a red-dot for a bunch of different pistols. But as far putting a red-dot on your pistol, it gets the job done.

Accuracy * * * *
The UM3 pistol sight mount stays pretty accurate. In banging the pistol around a bit and actually using it, the point of aim seemed to stay true. So this is a pretty constant system; I wouldn’t say you could throw your gun down range and go get it and have it all still be accurate, but I would never suggest doing that anyways.

Overall * * * *
Overall, I give the UM3 pistol sight mount 4 stars. This is because it works, and is a great way to get a red-dot on your pistol to try out, or just for fun. Red-dots are nice, they are fun, and they work well… so having the option of attaching one to a pistol is great, especially in a way that doesn’t require machining down the slide of your gun. If you have want to try a red-dot on your pistol, I’d say this is definitely a good start without a huge investment.

This post has also been posted on The Truth About Guns. Check out their site for tons of firearms and firearm industry news and information.

One comment

  1. While the mount works on the FiveSeven, it only slides back as far as the first notch on the the rail befor hitting and gouging part of the frame. Notching the left side of the mount, so it goes around the takedown lever, and notching the right side, so the lower edge it doesn’t hit the lower part of the frame, permits the mount to slide fully rearward. It’s also reported to be ‘known’ that some FiveSeven frames have cracked using this type of mount – though I haven’t located anyone to whom it actually happened.

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