Sig Sauer ROMEO5 1x20mm Red Dot Sight

By Randy Wakeman

Illustration courtesy of Sig Sauer.

Do you need a Sig ROMEO5 red dot sight? If your rifle, handgun, or shotgun has an M1913 Picatinny Rail on top, you very well might. Here is how Sig describes their ROMEO5:

"A Robust, compact red dot sight with 1x aiming solution optimized for today's MSR rifles, shotguns, carbines, submachine guns, and full-sized handguns."

There are currently (May 2018) four variations of the ROMEO5, with the differences being in the reticle, adjustment increments and the battery that powers the unit (one AAA, or one CR2032). The tested example is item number SOR52101, which has a 2 MOA red dot reticle and is powered by a single AAA cell.


  • 2 MOA Red-Dot provides 10 illumination settings (8 daylight plus 2 NV) for visibility in all light conditions.
  • MOTAC (Motion Activated Illumination) powers up when it senses motion and powers down when it does not. Provides for optimum operational safety and enhanced 50,000+ hour battery life.
  • Integrated M1913 Picatinny interface provides industry-standard mounting options for a wide range of applications.
  • Dependable waterproof (IPX-7 rated for complete water immersion up to 1 meter) and fog-proof performance.
  • Includes a M1913 Picatinny low mount riser and a co-witness 1.41 inch riser mount.


  • Item #: SOR52101
  • Reticle: 2 MOA red dot
  • Magnification: 1x
  • Objective clear aperture: 20mm
  • Eye relief: Unlimited
  • Adjustment increments: 0.5 MOA
  • Adjustment range: +/- 40 MOA
  • Battery: 1-AAA
  • Color: Black
  • Length: 2.47 in.
  • Width: 1.5 in.
  • Height: 1.52 in.
  • Weight: 5.1 oz.
  • 2018 MSRP: $239.99

This Sig red dot sight has a lot going for it, certainly compared to the many tube and mounting ring type red dots I have used over the years. It is relatively compact, a 1x no-magnification sight with a 20mm objective. It is an extremely tough unit that easily attaches to your rail with a reassuringly sturdy integral metal mount.

SIG SAUER ROMEO5 mounted on rifle

Above, it is mounted on my S&W M&P 15 in absolute co-witness mode. If you prefer the lower 1/3 co-witness instead, no problem: the spacer is included.

The "SIG SAUER Electro-Optic Infinite Guarantee" is a guarantee that isn't. It refers only to the body, while the electronics have a five year warranty from date of manufacture, with no easy way to tell when it was manufactured. Having a more candid five year warranty from date of purchase would be more straightforward.

The 50,000 hour battery life from one AAA battery is impressive, as is the built in motion sensor that turns the unit on. The buttons for illumination adjustment are generous and easy to use. It is IPX-7 rated, so you will not have to worry about the unit flooding out in heavy rain.

Unlike some red dot sights, the ROMEO5 is plenty bright enough for use in broad daylight and dims down nicely for after sunset or nighttime use. It has ten levels of brightness, where some competing red dot sights have as few as three.

Somebody at Sig did some good design work here, for everything, including the bikini cover, is thought through. The included Torx wrench for mounting the unit has a flat on one side that fits the windage and elevation adjustment slots.

It is hard to get MOA accuracy out of a 10 MOA device. Several red dot sights have dots that are too coarse; 10 MOA and 8 MOA sights are common. The 2 MOA dot of the Sig Romeo5 is more precise.

This is a very good red dot sight. Certainly, on an Armalite platform rifle it is ideal. It is also a good choice on a shotgun for turkey hunting, or essentially any gun that has a top mount Picatinny rail.

The Sig ROMEO5 1x20mm sells for less than some of the premium red dot sight options, but in most applications it is as good, if not better. It is a fine red dot sight that sells for about $200.

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Copyright 2018 by Randy Wakeman. All rights reserved.