Ultimate Rifle Versatility: Trijicon’s MRO SD and 3X Magnifier

I first became interested in the AR-15 platform in the mid-1990’s. Prior to that, I was a member of my former agency’s SWAT Team and was issued an HK MP5. M4-style carbines are now at the forefront as they can be effectively used for everything from up close out to hundreds of yards.

 

At one point, I owned more than a few AR platform rifles, but I have narrowed things down considerably. My need for a carbine at this time in my life has changed greatly as I’m no longer in law enforcement and I’m certainly not going to war, so I have one go-to carbine that I have set up to fill my perceived need.

I want it to be sleek, light, easy to use and void of unnecessary accessories. It’s reliable, has an optic, a sling, and a compact weapon light. It has a skeletonized stock and I use 20-round magazines to further enhance its compactness. I’ve thought about adding either a variable powered optic or a magnifier to increase reach, but have been reluctant to do so as adding one of those adds to the bulk of my sleek, light carbine.

While zeroing distance has long been debated, I have found the 36-yard zero works just fine for me while using my Trijicon MRO red dot. I’ve been able to hit a ten-inch gong at 300 yards, so my thought wa,s why do I need additional optical enhancement?

Life is funny, though, and just about the same time I finally decided that, I was walking the floor at the 2025 NRA Convention and stopped at the Trijicon booth and came across the latest updated version of the MRO, the MRO SD and their palm-sized 3X magnifier.

The Trijicon MRO (miniature rifle optic) is a compact reflex sight intended for use on all long guns to provide fast-on-target acquisition. Like most reflex sights, the MRO is designed to be used with both eyes open, providing the shooter with enhanced situational awareness. The MRO also features ambidextrous brightness controls, sub-flush adjustment knobs, advanced lens coatings, and a fully sealed, waterproof, hard anodized forged 7075-T6 housing.

The new MRO SD has been redesigned to offer a much longer battery life…three years for either the red or green dot models. It also offers improved windage and elevation adjustments over its predecessor, and it’s designed to maintain tight zero retention if dropped or otherwise abused.

The brightness adjustment dial is usable with either hand without having to remove the shooter’s hand from the fire control. The capless design uses sub-flush adjustment knobs which eliminates lost caps, snag hazards and ensures against inadvertent re-adjustment or loss of zero.

The MRO SD’s advanced electronics are warrantied for five years while the multi-coated lenses provide superior clarity and light-gathering capabilities with zero distortion for a crisp dot reticle. The re-engineered objective lens allows for enhanced optical performance and magnifier compatibility.

I could not use my gun club range for this test as it offers 100 yards as a maximum distance. While this is just fine for my typical practice, I felt like the 3X magnifier “deserved” a little more distance for a proper test. I reached out to a buddy who owns a farm and he allowed me to set up an impromptu range.

I zeroed the MRO SD at 36 yards using a bench rest on a three-inch square sticker of the type I normally use as a pistol target. Like most optics from Trijicon, the MRO SD was mostly zeroed at the factory and it only took a few clicks left and a few clicks up to get it right where I wanted it. I fired only four rounds. After the close zero, I moved back to 300 and assumed a grounded bench rest position to see if I would be close. My target was an AR-500 12-inch gong plate suspended from two chains. Since my carbine is intended for combative purposes, I felt like this “minute of chest cavity” test would be more than valid for my intended purposes.

I first tried to hit the plate with the MRO SD alone just to see where I stood. It took a few rounds, but I was able to hit the plate after a few tries. I then flipped up the magnifier. I should note that the flip up mount that came with the magnifier was quite positive, locking the optic in the up or down position solidly while at the same time being easy to operate. With the magnifier flipped down, I was able to flip up my irons and shoot through the MRO with ease. Some will criticize me for not having the irons up all of the time, but these old eyes don’t need any additional “clutter” in the sight picture.

While I was able to hit the plate with the dot optic alone, it was much easier with the magnifier in place. This is not surprising; isn’t that what a magnifier is for? If the target is more visible then accuracy will be enhanced. Like all products from Trijicon, the quality and durability of the MRO SD/3X magnifier are readily apparent. The view is crisp and clear with no distortion, even when mating the two optics.

They are not the cheapest options on the market, but they will likely last you the rest of your life and sometimes buying once can save money. When was the last time you “saved money” only to spend more correcting your mistake?

Yeah…me too.