The RMSx – Mini But Big

It’s rare that a modern gun is too small for a red dot optic. You really have to go below the pocket pistol-sized gun to really exclude the use of red dots. The red dot revolution ripped across the land and spread to guns both big and small. A British company called Shield was the first to create a commercially successful micro red dot designed for the single stack 9mm and micro-compact market, and it was actually a rifle sight ala RMR piggybacking ACOG prior to that. The Shield RMSc set the standard footprint all the little guns use today. Shield innovated once, and they’ve recently done so once more with the Shield RMSx. 

Little guns have little optics with little windows. It’s not a huge problem, and little optics with little windows keep the gun nice and small.

With that said a bigger window can be very nice. Companies like Leupold and SIG certainly try their hardest to produce optics with giant windows. A big window might not matter to top-tier shooters, but for us mere mortals, a nice big window allows you to mess up. 

The Shield RMSx provides a massive window. Way bigger than any other micro red dot on the market. If your pistol has a Shield footprint, specifically the RMSc, then the RMSx provides a massive window about 80% larger than a standard Shield RMSc

Into the Shield RMSx 

The Shield RMSx is built for competition, according to the website, and it does lack some features your modern tactical shooter might want. For example, it’s auto adjust only, and there is no on and off. When put away in the dark, the dot dims to nothing and effectively turns it off. The battery is mounted through the bottom of the unit, and the whole thing has to be removed to swap the battery. 

Additionally, the lens is made of polymer. That’s mostly okay, glass is preferred, and the Shield RSMc now has a glass option.

The main problem with polymer is that it tends to scratch easier, but for a deep concealed gun, this isn’t likely to be a big problem. In Shield’s defense, they do advertise the RMSx as a competition optic. 

This little fella weighs .617 of an ounce and does have an aluminum body. The dot brightness is night vision compatible, and the highest setting claims it works in the brightest of light. The battery will last 2 to 3 years, depending on the average use. The reticle is either 4 or 8 MOA. 

Also, the optic is designed and built in the United Kingdom. 

The Big Little RMSx 

My go-to for my carry gun has been the Holosun 507K on my P365XL. I popped the 507K off to give the RMSx a little run. Immediately the big window and the brilliantly clear lens were a major positive. I greatly enjoyed the big view window. I mentioned prior that a top-tier shooter doesn’t likely need a bigger window, their presentation covers it. However, a bigger window gives you a little leeway on your presentation and makes tracking the dot faster. 

Being able to find the dot means you can get the dot on target faster and make target transitions faster. It’s easy to get your gun going and put more lead on your target with less time required. This specific window is massive and makes it easy to get behind and find the dot. 

It surprised me, and while I didn’t notice a huge difference in the time, I did find the optic to be more intuitive to use and loved looking through the massive clear window. The border of the RMSx is plenty thin and allows you a nice, almost uninterrupted view of your sight picture. 

Tossing Lead 

The 4 MOA dot on my RMSx is crisp, easy to see, and a nice perfect little dot. It’s the perfect size to be eye-catching and easy to see. The auto adjustment of the RMSx is spot on. It gets super bright in the brightest conditions the Florida sun throws at us. My main problem with an auto-adjusting dot is how it adjusts when mixed with a handheld or weapon light. Oftentimes it gets washed out once the light pops on. 

I used a 1,000-lumen ASP light in a dark room to test the auto adjustment, and was impressed. I started with the light off, capable of seeing the dot. Then I hit the light, and the dot adjusted faster than I could comprehend. It spun right up without complaint. 

The optic comes with an Allen key and a little dial to allow you to measure your adjustments and guide you in the right direction. The adjustments are tactile, and you can feel and hear them.  

At the range, the little optic held zero, and over a few hundred rounds proved its willingness to serve. The big window really showed its strength when it came time to shoot with one hand, both dominant and non-dominant shooting. That’s where I’m really sloppy, and the big window made such a big difference in finding the dot between shots and scoring solid hits when needed. 

Is Bigger Better? 

If I was a better shooter, maybe bigger wouldn’t be better, but I’m not, so it is. The little extra leeway it gives is very nice, especially with a small gun. The downside is that your gun is a little bit bigger. I would prefer a glass lens on top of manual adjustments, but this might be the biggest optic possible for small guns, and there is something to be said for that ratio. 

It’s not for everyone, but it’s for me, and I think the RMSx is a solid choice in the micro compact market. 

Travis Pike
Travis Pike is a former Marine Machine gunner who served with 2nd Bn 2nd Marines for 5 years. He deployed in 2009 to Afghanistan and again in 2011 with the 22nd MEU(SOC) during a record setting 11 months at sea. He’s trained with the Romanian Army, the Spanish Marines, the Emirate Marines and the Afghan National Army. He serves as an NRA certified pistol instructor and teaches concealed carry classes.