TFB Review: SIG Sauer ROMEO2 Modular Handgun Red Dot Sight

Luke C.
by Luke C.
REVIEW: The SIG Sauer ROMEO2 Modular Handgun Red Dot

I first took a glimpse of the new SIG Sauer ROMEO2 modular handgun red dot back in the winter of 2020 when SIG Sauer invited me out to SIG Electro-Optics in Oregon. There I was able to get a look at how they were constructed, and who was making them, and then SIG also gave us a chance to get a little bit of trigger time behind the ROMEO2 before we were all sent home. Fast forward to 2022 and I was finally able to get my hands on one for testing and evaluation – my way. The ROMEO2 is attempting to do something that, to my knowledge, has never been done before with a pistol-mounted red dot. The ROMEO2 is modular in that the user can quickly and easily add the included protective metal shroud and polycarbonate lens to seal the interior of the optic from outside moisture, dirt, dust, and debris. How well does this work out? Let’s find out!

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REVIEW: The SIG Sauer ROMEO2 Modular Handgun Red Dot

TFB Review: SIG Sauer ROMEO2 Modular Handgun Red Dot Sight

There are actually three different versions of the SIG Sauer ROMEO2 red dot. The version we’ll be reviewing today is SKU number SOR21300 which comes standard with a 3 MOA red dot only. Two other versions are also available including a 6 MOA Red Dot version ( SOR21600), and a Circle Dot version ( SOR21000). Other than differences between the reticle sizes and styles, all three versions feature the same basic specifications.

ROMEO2 Specifications:

  • Adjustment Increments: 1 MOA
  • Magnification: 1X
  • Objective Lens Diameter: 30 mm
  • Battery Type: (1) CR2032
  • Run Time: 25,000 Hours at Medium Setting
  • Illumination Settings: 12 daylight/ 3 NV
  • Overall Length: 1.84 in
  • Overall Widge: 1.32 in
  • Overall Height: 1.12 in
  • Footprint: ROMEO1 PRO (without the two front bosses)
  • Features: Magnetic Activation, Motac Motion Activated Illumination System, Spring Loaded battery tray
  • Designed, developed, tested, and assembled in the USA.
REVIEW: The SIG Sauer ROMEO2 Modular Handgun Red Dot

First Impressions

Right out of the gate, the bare ROMEO2 looks kind of like a ROMEO1 PRO. Everything from the lens shape, body size, and controls layout look very similar but there are a lot of changes that make the ROMEO2 stand apart from its older cousin. First, SIG has made the decision to move the battery tray from the top to the side and given it a push-button spring-loaded operation so that battery changes can be made quickly and easily without any hardware to use. Second, the controls on the left-hand side do not protrude from the body of the red dot and thus, there are no risks of inadvertent activation or changes in brightness settings.

REVIEW: The SIG Sauer ROMEO2 Modular Handgun Red Dot

Each SIG Sauer ROMEO2 red dot comes complete with a manual, LensPen, metal shroud, polycarbonate rear lens, and an optic-specific torque wrench that comes with three bits – one for every adjustable or screwable thing on the optic. The optic’s prescribed 28 in/lbs of torque for each piece of mounting hardware is again mirrored with the included torque wrench so there is no chance of over torquing and stripping the hardware or mounting holes.

REVIEW: The SIG Sauer ROMEO2 Modular Handgun Red Dot

I chose to mount my SIG Sauer ROMEO2 on my SIG Sauer P320 XCarry Legion, specifically because I thought the pistol/optic combo would make for a great competition gun for the upcoming InRangeTV Woodland Brutality 2022. Since I didn’t know what to come prepared for in terms of weather and environment, the ROMEO2 with its included shroud and waterproofing capability only made sense as my pistol’s primary optic.

REVIEW: The SIG Sauer ROMEO2 Modular Handgun Red Dot

I would rate both the glass quality and dot clarity very high. I have a quarter step of astigmatism in each eye and while that’s not much, it’s enough for me to notice a small starburst effect on most red dot optics. The glass clarity was very good but there was still a tiny bit of edge distortion but not enough to be noticed when you’re shooting. For those curious, the ROMEO2 uses an aspheric lens design which is much less prone to distortion and much better for light transmission – especially for use under night vision.

The ROMEO2 in a "naked" configuration. No rear lens and no shroud mounted.

The ROMEO2’s dot clarity is superb and didn’t bloom quite as much as other optics do. SIG Sauer accomplishes this via a Point Source Emitter which is more expensive to manufacture than a typical red dot LED emitter which uses a secondary lens to generate the dot. Point Source Emitters, on the other hand, use a unique LED chip with an integrated glass lens and produce an objectively clearer circular dot that is clear in shape and uniform in brightness. Is it completely necessary? Probably not but it’s something interesting I learned from the engineers that designed the ROMEO2 and its noticeable, especially during bright conditions.

Cool Features

The ROMEO2 has a lot of weird/neat features that come standard with all three types. The first we’ll mention is its MOTAC or Motion Activated Illumination System. MOTAC automatically turns the optic on or off based on the motion (or the lack of) it is detecting. However, MOTAC can be turned off and you can simply rely on its Magnetic Activation System. The Magnetic Activation System shuts the optic on or off when it detects the presence of a strong magnet. This is easily demonstrated by the included rubber cover that fits over the fully assembled optic and comes with its own neodymium magnet.

Note the small bulge in the front of the optic cover which contains the magnet that is used to turn off the optic while it is covered. This also works with duty holsters when a magnet is equipped.
REVIEW: The SIG Sauer ROMEO2 Modular Handgun Red Dot

That last odd/cool feature I’ll mention is the inclusion of a gas redirecting piece that nestles into the front of the optic just behind the ejection port of your pistol. This little plastic addition is optional but I opted to install mine in the hopes it would reduce the amount of cleaning I’d have to do and I’m happy to say that it works quite well. There will still be some buildup of carbon and unburnt powder around the edges of the glass but much less than expected.

REVIEW: The SIG Sauer ROMEO2 Modular Handgun Red Dot

Durability/Water Ingress

During Woodland Brutality 2022, the pistol stayed holstered in my Blackhawk Omnivore throughout the two-day-long competition. During those two days, we were exposed to no rain but did encounter our fair share of dust, mud, and debris. By the end of each day, the rear of the optic had collected a nice fine layer of dust on it and due to the design, I was able to brush this away quite easily. I also had the opportunity to run the red dot/pistol combo both before and after the competition and I didn’t encounter any issues with fogging, reticle failure, loss of zero, or premature battery failure.

REVIEW: The SIG Sauer ROMEO2 Modular Handgun Red Dot

The ROMEO2 comes with an IPX7 rating meaning it can be submerged in 1 meter of water for up to 30 minutes. The nearest source of water to me is a 5-foot-deep swimming pool so I decided to toss it in there – from 3 stories up while it was still attached to the P320 XCarry Legion.

To get right to the point, the optic and the pistol handled the water just fine. Now, a lot of you will say that the ability to move from an open emitter design to an enclosed emitter design is sort of moot because the optic itself is not nitrogen purged. This means that any moisture left inside could potentially fog up the interior of the optic and obstruct your sight picture. However, I think most people that think this are looking for the one-in-a-million situation that just won’t arise. In essence, you’re the one who is going to decide whether or not you’re going to put the full around on there and if you’re going to do it, you’re ultimately responsible for making sure no moisture is present inside the around before its assembled.

The side loading battery tray

Aaron Cowan who was with me at the initial media event for the ROMEO2 has done some pretty extensive testing with his own ROMEO2 and he and I are in agreement that the lack of nitrogen purging is basically a non-issue if you’re taking the proper precautions. Aaron recommends that you take the necessary steps to eliminate any moisture from the optic before putting on the full shroud.

REVIEW: The SIG Sauer ROMEO2 Modular Handgun Red Dot

Immediately after tossing the gun into the pool and letting it sit around for about 5 minutes, I removed it from the water, took it back home, and immediately put it inside the freezer with the water still on it. After 6-8 hours of freezing time, I removed the pistol and saw that the dot was still operating normally, but my gun had locked up due to ice buildup. Suffice it to say, the ROMEO2 is one durable pistol-mounted optic.

REVIEW: The SIG Sauer ROMEO2 Modular Handgun Red Dot

Final Thoughts

So who is the ROMEO2 for? Most competitive shooters would probably scoff at the shorter window, and concealed carriers would probably think that the optic is a bit too chunky to be concealed properly. This leaves us with duty. As a duty optic for military, law enforcement, or private security, I think the optic would shine in just about any conditions. One of the primary experiences that turned me on to close emitter designs is that snow, rain, and dust can easily get into an open emitter design and skew your sight picture or outright block it. The enclosed emitter design prevents any of that crap from getting inside to where the emitter is and therefore, a simple swipe of the rear lens is all that is needed to get back into action.

REVIEW: The SIG Sauer ROMEO2 Modular Handgun Red Dot

Check Prices on SIG Sauer ROMEO2 Modular Reflex Sights

Should you buy the ROMEO2? That depends. I personally really like mine just because it’s absolutely durable. For competition purposes, I still think I’ll be using my Trijicon SRO because of its giant window, but for literally anything else, the ROMEO2 fits the bill and is far more durable and adaptable than any of my other pistol-mounted red dot optics. However, as always, I’d like to hear your thoughts on the SIG Sauer ROMEO2 red dot optic. Is this a red dot optic you’ve been looking forward to picking up? Is the price too steep for what they’re offering you or do you think you’ll be finding one sitting atop one of your pistols in the near future? Let us know down in the comments!

REVIEW: The SIG Sauer ROMEO2 Modular Handgun Red Dot
REVIEW: The SIG Sauer ROMEO2 Modular Handgun Red Dot

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Luke C.
Luke C.

Reloader SCSA Competitor Certified Pilot Currently able to pass himself off as the second cousin twice removed of Joe Flanigan. Instagram:

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6 of 21 comments
  • Ahab Ahab on Jul 30, 2022

    This has been done with another pistol optic before: the Burris Fastfire 4.

    • See 3 previous
    • Ahab Ahab on Aug 01, 2022

      @erwos Congrats?

  • Hyok Kim Hyok Kim on Aug 03, 2022

    How does this compare with holosun 507c acss vulcan green dot?