Review: Trijicon SRO Reflex Sight

posted on January 7, 2020

A reflex sight mounted onto the slide of a semi-auto pistol takes a serious beating. The G-forces created by the rapid rearward acceleration upon firing, the sudden stop at the end of the slide travel, the sudden acceleration forward to battery, and the abrupt stop there, do some very unkind things to delicate internal electronic components.

The series of RMR compact reflex sights by Trijicon has earned a solid reputation for surviving the “slide ride.” The RMR on my S&W M&P C.O.R.E. has run over 7,000 rounds without a hiccup. However, many RMR shooters (myself included) have wished the sight window was bigger.

In 2019, Trijicon granted our wish with the new SRO (Specialized Reflex Optic).

The Trijicon SRO (MSRP: $749, sight window is the same width as the RMR, but replaces that unit’s narrow rectangular window with a round window that provides a significant increase in vertical view. The round window measures 0.98 x 0.89 inches. The larger size gives the SRO a weight of 1.58 ounces, compared to the RMR weight of 1.2 ounces.

Trijicon SRO | Battery Compartment
The top loading battery compartment precludes the need to remove the sight from the gun to replace the CR2032 battery.

Like the RMR series, the SRO uses a single readily-available CR2032 lithium battery. Unlike the RMR, this battery loads from the top. There is no need to remove the sight from the gun to change batteries and a bottom sealing plate is not needed.

Beyond those obvious differences, the SRO operates in the same manner as the RMR Type 2 Adjustable. There are two control buttons on the sight—a Plus button on the left side and a Minus button on the right. There are eight brightness levels that can be selected, with 1 being the dimmest and 8 being the brightest. The top six (3 through 8) are for daylight use, while the bottom two are for night-vision gear. Trijicon claims a battery life of three years continuous use at the mid-point Number 4 brightness setting.

To turn the sight on depress either of the two buttons. It will come on in the Auto-Adjust mode. If that works for the shooter, fine. If not, press the Plus button to increase brightness or the Minus button to decrease. If a shooter manually adjusts brightness and then wants to go back to Auto-Adjust, just depress both buttons for less than one second. To turn the sight off, depress both buttons simultaneously for four seconds.

RMR vs. SRO sight window
A larger window on the SRO (r.) provides a significantly larger field of view compared to the RMR, and the author found it impossible to lose the dot on recoil.

The SRO uses the same mounting footprint as the RMR and fits existing slide or Picatinny rail mounts for the RMR. But there’s a caveat. The SRO is longer than the RMR. There is an overhang in the front that is approximately ⅜ inch beyond the RMR length. This needs to be considered when mounting to a slide because (as Trijicon notes) if the overhang extends forward over the rear of the ejection port malfunctions can occur. If a shooter has an RMR on their slide now, they would be wise to measure the distance from the front of that sight to the ejection port rear to see if the SRO is a good fit with that mounting screw position.

The SRO is available with a 1 MOA, 2.5 MOA, or 5 MOA dot. The test sight I used was the 2.5 MOA model. That’s a bit small for my eyes on a handgun, But I unscrewed the RMR from my C.O.R.E., and using the same screws I popped the SRO in its place. It fit perfectly, although the over hang was right at the back end of the ejection port. The next step was my backyard range.

The big window was a treat, and it perfectly co-indexed with the iron sights on my C.O.R.E. The 1 MOA windage and elevation adjustments got it zeroed quickly from a 25-yard bench, and I started running transition drills. The 2.5 MOA dot was small, but nicely rounded and very precise. I did have to kick it up to 8-power to be comfortable, although a 5 MOA wouldn’t have required that.

SRO on M&P C.O.R.E.
The SRO has a front overhand that extends beyond the RMR length, but worked perfectly on the author’s M&P C.O.R.E.

The larger window was impressive. I have “lost the dot” on recoil with my RMR a few times and had to play “Where’s Waldo,” but I couldn’t lose this dot. A match was next. Schedules prevented IDPA or USPSA, but a six-stage Steel Challenge match was available.

I hadn’t shot SCSA Carry Optics in several months and was a bit rusty. But with the little dot cranked up to 8-power I had an effective sight. The big window made acquiring the first target from the holster easy, and transitions were even easier. No matter how fast (or sloppy) I was, it was impossible for me to lose the dot. I thought the sight was letting me shoot pretty well. At the end of the match I found out just how well.

Despite the rust, I bested four of my peak Classifier times on the six stages, and got within 0.5 seconds of peak on the other two. I would have preferred a 5 MOA dot, but I think I’ll leave this one on my C.O.R.E. It’s hard to argue with results, and that bigger window made a significant difference compared to my RMR.

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