Steiner MPS Closed Pistol Red Dot: Review

This closed, all-metal 1X pistol red dot has a solid battery life, easy controls and is compatible with the Aimpoint ACRO mounting pattern.

January 09, 2023 By James Tarr, Handguns Editor

If you’ve ever been in the market for rifle optics, the name Steiner should be familiar to you. A German company which has been in the optic business for seventy-five years, they are known for excellent glass and quality electronics. Their latest product is the Steiner MPS or Micro Pistol Sight. The MPS is an enclosed red dot sight meant to ride on a pistol slide. In appearance alone it will be compared to the Aimpoint ACRO, as they are both rectangular, enclosed red dot optics, and in fact the MPS uses the ACRO mounting footprint, although a mounting plate is available that will fit it to the common Docter footprint.

Steiner MPS Closed Pistol Red Dot — Tarr thinks the light, compact MPS is perfectly suited to short ARs. It uses the Aimpoint ACRO footprint. Here it is in a Reptilia Corp mount atop a CZ Scorpion EVO pistol. (Firearms News photo)

The MPS is 2.17-inches long, 1.25-inches tall, and 1.2-inches wide. The window is 0.83-inches wide and 0.63-inches tall, and the optic, without battery, weighs 2.05 ounces. For comparison (because I know you’ll be curious) the ACRO P-2 is 1.9 x 1.3 x 1.2 inches and weighs 2.1 ounces. The ACRO’s window is square, 0.63 x 0.63 inch. The MPS’ housing is machined aluminum. The emitter is at the top of the optic body, and so you’ll see the window sits very low in the sight. The rear lens is flat and vertical. The front lens is both curved and angled downward, to reduce light reflecting off it in a tactical environment. The battery compartment is on the top of the optic. It has an internal O-ring seal and you’ll need a flat-head screwdriver to open it. It almost looks like you could use the rim of a cartridge to open it, but when I tried with a 9mm case, I just succeeded in chewing up the shallow slot. Windage and elevation adjustments are 1 MOA per click, and the clicks were audible and satisfying. You’ll need the same small flat-head screwdriver to zero your MPS as you will to install the battery, and Steiner provides the tool to do that.

The MPS is powered by a CR1632 battery advertised to provide 13,000 hours of service at the medium brightness setting, and it boasts a user-selectable auto-off function after 13 hours. A flashing dot indicates low battery. The MPS sports a 3.3 MOA dot, and eight brightness settings (six daytime, two NV). Dot color is red. The dot seemed nicely crisp, and at its highest settings was more than bright enough to see and use outdoors on a sunny day.

The brightness controls are rubberized buttons on the left side of the housing: “+” and “-”. They click when you press them. Press and hold the “–” button to shut off the dot. Press the “+” button to turn it back on. It turns back on at the previous brightness setting. On my test sample the glass lenses were free of imperfections, but did display a faint blue tint that will likely go unnoticed under most conditions.

Now for the comparison: the Aimpoint ACRO is priced $75 higher as I write this, but what you get for that higher price is better water resistance (35 meter submersible versus the MPS’ 10 meter) and a longer battery life. As the ACRO is powered by the larger CR2032 (compared to the CR1632 in the MPS) the ACRO has an advertised battery life of 50,000 hours, compared to the MPS’ 13,000 hours. That is a significant difference, but considering 13,000 hours is still nearly 2 years, and you should be changing out the batteries on your optics every year, I don’t consider it that important. Also note that the ACRO does not have an auto-off function, but the Steiner MPS does have a user-selectable auto-off function.

Closed optics, like the MPS do much better in wet environments than open optics like the Trijicon RMR. If you get water droplets on the lens of an enclosed sight you will still be able to use it, as the projected dot is internal, and unaffected. If you get a water droplet on the inside of an open red dot optic lens it may completely diffuse the dot and make it unusable. Plus, with an open optic dirt, snow or even lint can get in and block the emitter, meaning no dot. This functionality of these closed sights helps counteract what I feel is a significant negative—their size and appearance. The MPS looks like a mini loaf of bread sitting atop a pistol slide, just like the Aimpoint ACRO. I like them in spite of their appearance, not because of it.

I’m still generally opposed to mounting red dots on carry guns, as I feel their disadvantages outweigh their advantages, but the Steiner MPS is another quality alternative if you want to do so. Where I think it (and the Aimpoint ACRO, Trijicon RMR, etc.) shine is as compact red dots atop compact AR-15s and similar guns. If you’ve got an AR-15 pistol or SBR, you will likely want to top it with a smaller, lighter optic, and something like the MPS is just perfect in that role. For testing I mounted the MPS in a flattop AR mount from Reptilia Corp, and at various times used it atop a CZ Scorpion EVO 9mm pistol and an AR-15 pistol. It performed exactly as advertised.

MSRP on the Steiner MPS originally was $574.99, but I see they’ve now dropped that by fifty bucks—likely to draw sales away from the Aimpoint ACRO P-2, which is $599. Current retail price on the MPS is $524.99 from Steiner directly, and it is also available through most distributors.

About the Author

James Tarr is a longtime contributor to Firearms News and other firearms publications. A former police officer he is a USPSA Production Division Grand Master. He is also the author of several books, including CARNIVORE, which was featured on The O’Reilly Factor. His current best-selling novel, Dogsoldiers, is available now through Amazon.

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