Competition Reviews Self Defense

Trijicon RMR versus Trijicon SRO

Here is a little head to head comparison between the Trijicon RMR and Trijicon SRO. They are both fantastic red dot sights and each has pros and cons.

After having reviewed both, the Trijicon RMR and the Trijicon SRO, red dot sights, I’ve had folks ask me which one they should get? Or, which one is better? As such, I figured it wouldn’t hurt to do a little side by side comparison.

Let’s start with a little table that compares some of the things I think matter for a comparison.

Window Size22x16mmBigger
Dot Size1, 3.25, or 6.5 MOA1, 2.5, or 5 MOA
Overall Size1.8″ Length x 1.2″ Width x 1.0″ Height2.2″ Length x 1.3″ Width x 1.4″ Height
Weight1.2 oz1.6 oz
Battery LifeOver 4 years from 1 CR2032 batteryOver 3 years from 1 CR2032 battery
Brightness Adjustments2 NVD 6 Regular2 NVD 6 Regular
Manual (16.5 hour time out)
Automatic Lock Out
Automatic Lock Out
Manual Lock In
ReliabilityAbove AverageAbove Average
DurabilityAbove AverageAverage

That table should be enough to help some folks make a decision between the two, but I suspect other folks are curious about my opinion. So here we go.

The window size on the RMR is a very good size. It’s big enough that the dot is easy enough to see and track. Being able to track the dot is a good thing because it gives the shooter feedback that can be used to make adjustments to one’s shooting technique while training or while shooting. Compared to the window on the SRO, the RMR window size feels small. The larger window on the SRO makes tracking the dot easier. In fact, with a strong enough grip the dot may not leave the window at all. Easier dot tracking translates into more feedback which is something I value when shooting competitively or sometimes when I’m training.

The dot sizes are what they are. Each red dot is available in three different sizes. My experience is limited to the 3.25 MOA dot on the RMR and the 2.5 MOA dot on the SRO. I won’t hash out the considerations between small and large dots here since I’ve talked about the considerations in both of the dots’ respective reviews before. Side by side, the 3.25 MOA dot on the RMR is noticeably larger and I find it to be marginally faster to see when I need to see it. However, that faster feeling is purely subjective as I haven’t gathered and compared split time differences between the two dots on the same gun.

The SRO is bigger and weighs more than the RMR. For me this isn’t a big deal, but it is something to consider. The larger dimensions can make the SRO a bit more difficult to conceal since it is 0.4″ taller and 0.1″ wider than the RMR. The additional 0.4″ in length of the SRO is found in the front which just hangs out there. The part that literally hangs out front can interfere with rear iron sights that have been placed forward of the pistol optic mounting area. Additionally, the SRO may hang over the barrel hood which can interfere with reliable ejection of spent brass. As a result, the SRO will not work with some pistols.

Both the RMR and SRO have the same number of brightness levels including two settings compatible with night vision devices. However, brightness operation modes are not identical. The RMR doesn’t have a manual brightness lock in feature which prevents accidental brightness adjustments. Additionally, the RMR’s manual brightness mode times out after 16 hours and returns to automatic brightness mode. The time out, dubbed “Battery Conservation Mode” by Trijicon, was implemented to maximize the battery life of the RMR which is over 30% better than the battery life of the SRO. I don’t see the difference of battery life being a significant difference for folks, like me, who change out the single CR2032 battery annually. Some folks will complain about having to remove the RMR from the pistol in order to change the battery which is located under the sight although I haven’t found it to be problematic. Sure, removing and reattaching the RMR results in having to go the range and reconfirm zero. However, reconfirming zero is something folks should do periodically anyway.

I’ve shot thousands of rounds through a pistol with the RMR mounted to it and it keeps on ticking. The round count on the SRO is much lower. As of writing this post, I haven’t experienced an electronic failure or a loss of zero on either optic. I know that is anecdotal. I have heard a handful of accounts of folks experiencing electronic component failures with both optics. Sage Dynamics has a few similar accounts documented in their Miniaturized Red Dot Systems for Duty Handgun Use white paper. However, the accounts of this failure appear to be low in number compared with other red dot makes and models. Additionally, I haven’t run across a single account of either of these red dots losing their zero. For these reasons, I consider the SRO and RMR to have above average reliability.

I’m not particularly hard on either of these optics. Sure, I shoot quite a bit, but I’m only shooting 9mm, I’m not doing a high number of one-handed slide manipulations, and I’m not purposely drop testing them. However, Aaron Cowan does beat the living daylights out of the optics he tests for the Sage Dynamics white paper I’ve already referenced. Based on that data, which I trust, I would describe the RMR to have above average durability and the SRO to have average durability.

Price wise, both of these dots are in the upper end of the open emitter pistol mountable red dot sights spectrum. The SRO is slightly less than 10% more expensive than the RMR.

So which one should you get? It depends on what one is planning to do with it. My suggestion for folks who are buying their first red dot and don’t plan on buying additional ones is to go with the RMR. Especially, if the red dot will be going on a pistol that one may depend on during a defensive encounter that requires the use of deadly force. Personally, I keep the RMR on the carry gun. I have started using the SRO for competitive shooting matches. I practice and train with both. The thought of running the SRO on a carry gun has crossed my mind many times and perhaps someday I will do it, but I haven’t yet due entirely to greater durability of the RMR.


  1. Good summary. I see very few students running SROs on concealed carry guns. SRO is super popular on competition guns in USPSA. I had an SRO, tried running it on my Glock 48 and encountered all the problems you describe with printing, and not working with any holster I had cut for a red dot. There are many other non-Trijicon options that fit the RMR mount (Holosun and Swampfox for example) anyone looking for a non RMR option should consider.

  2. I stopped reading after your very first sentence: “the window size on the RMR is a very good size”. That is absolutely incorrect on all levels. I bring a lot of guests to my club to go shooting. Many are ex military and cops (which contrary to popular belief many don’t own or shoot fancy guns with red dots). Literally 80-90% of them asked me if the RMR was off because they couldn’t see the red-dot on it – that’s how small the viewing window and viewing angle is. Better than iron sights? Yes… but just barely. Sure, with training it can be like second nature, but even 10+ years later I still have to sometimes remind myself to aim like I’m using regular iron sights just to be able to finally see the red dot.

    1. Sounds like we have a difference of opinion. I should have probably elaborated a bit more on why I think it’s a very good size, but at least I can do that now. The window is a good compromise big enough to allow tracking of the dot during a course of fire with proper technique but not so big that it gets in the way when carried for defensive purposes. The are smaller optics that give up even more view port for better comfort and concealment. And there are others, like the SRO, that provide more window and are therefore easier to use at the cost of weight and bulk. It’s all trade offs.

      As far as my opinion being “absolutely incorrect on all levels”, you are certainly entitled to your opinion. However, it’s worth pointing out that the RMR has, for quite sometime, been considered the gold standard by which all other pistol mountable optics are measured against by folks who are far more qualified than I am on the subject.

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