Sig Sauer’s Compact Red Dot Sight: The ROMEO5 1x20mm


The ROMEO5 is designed with sleek angles and sharp edges. This optic is as robust as it looks.

The Sig Sauer ROMEO5 compact red dot is the perfect balance between lightweight and small while maintaining a large field of view and strength due to its sealed design. This optic is perfect for self-defense situations and range visits alike. Because the ROMEO5’s infinite eye relief and M1913 Picatinny mount options included, this sight can be attached to virtually any firearm. The small 2 MOA dot with 10 brightness settings and 0.5 MOA adjustment values make this a fairly precise optic which ultimately leads to accurate results from the shooter despite the distance of engagement. And of course, with its $179 MSRP for the SOR52001 model, it is plenty affordable for the average shooter.

All boxed up and pretty: I couldn’t wait to get this optic out of the box and on my gun.

I was very excited to get the Sig Sauer ROMEO5 compact red dot because I had the perfect gun to put this optic on; a Ruger AR-556 MPR chambered in the hard-hitting and abusive 450 Bushmaster. This gun and the ROMEO5 went together like bread and butter because of my application. I wanted a gun that I could use on guided bear hunts that could be useful in up close and personal situations as well as mid-range engagements if needed. This same line of thought is why a person would choose the Romeo5 for any other self-defense situation, whether it be a dangerous animal or an armed human enemy.


After putting tons of rounds through the 450 Bushmaster while using the Sig Sauer ROMEO5 I was concerned that I would have a POI shift due to the heavy recoiling round. However, I did not observe anything of the sort. The scope stayed zeroed and reliable from the beginning of its use till present and I have no doubt that it will continue to do so. However, in the event that something were to happen, Sig Sauer’s Electro-Optics Infinite Guarantee has my back if I were to physically damage the optic, regardless of fault or reason. This coupled with the Electronic & Tritium Limited 5-year Warranty allows me to rest at ease knowing Sig stands behind their product.

Because of the ROMEO5’s infinite eye relief, the user can decide where they want to place the optic on their firearm depending on their own preference. The riser that is included doesn’t only allow for co-witness iron sight setups but also keeps the optic at a comfortable height which allows for a comfortable cheek weld.

An accuracy robbing phenomenon that plagues red dot optics is parallax, which I was a bit concerned about while using the ROMEO5, I will admit. I was paranoid about keeping my head in the exact same spot from shot to shot in order to produce the best accuracy results. Finally, I got tired of worrying about this and fired a 10 round, 100-yard group using the ROMEO5 while changing my eye location between shots. Then, I compared these results with a 100 yard group using the Leupold MK5 HD 5-25×56 (an optic for a totally different game) and I only saw a 15% difference in accuracy which could likely be attributed to the magnification differences between the two optics and thus my ability to compare the same level of precision. In the end, I was happy with these results and I can comfortably say that the ROMEO5 does not have any significant amount of parallax.


The ROMEO5 comes standard with a high riser that is designed to be absolute co-witness with most iron sights with its nominal mount height to an optical axis of 1.41 inches. This optic also comes with a low profile mount that can be interchanged with an included T10 Torx wrench. To swap these mounts, all it takes is the removal of the Torx bolts and replace the undesired mount with the mount you wish to use. From here, just re-install the Torx bolts to hand tight and then an extra ¼ turn, or approximately 20 inch-pounds.

The ROMEO5 comes with two different mounts, a low profile and a raised mount which are easily interchanged and do not need to be removed when changing the battery on the optic.

The ROMEO5 has a front lens that features a high-performance red-notch coating which aids in light transmission and makes the red dot crisp and clear. This dot has 10 illumination settings as mentioned which are made up of 8 daylight settings and 2 for night vision compatibility. In order to extend the life of the optic, Sig designed it with a motion activated illumination control, or what they dubbed “MOTAC.” This feature powers down the red dot when the optic is motionless for 120 seconds, and then powers back on when the optic senses motion. Together with a powerful CR2032 lithium battery (or AAA in other models), the ROMEO5 is expected to run for 40,000 plus hours of normal use. This battery is side loading in the CR2032 battery models and front loading on the AAA battery models. In both cases, the battery can be changed without affecting the zero of the sight that you have set.

This red dot has an IPX7 waterproof rating, which lets you be at ease no matter the weather conditions. This particular day that I was shooting, it was raining outside and it did not interrupt my plans because of the capabilities and warranty of this optic.

I already mentioned it, but I cannot stress how rugged the ROMEO5 red dot sight is.  The housing is made from cast aircraft grade aluminum for maximum durability. This optic is waterproof with an IPX7 rating which means it can be submerged in water up to 1 meter deep. Because this unit is totally sealed, it is also fog proof. And of course, if anything were to happen to the ROMEO5, Sig Sauer’s warranty will have your back.


In the model ROMEO5 red dot that I had, the battery is changed on the side of the optic. Simply unscrew the cap and install the CR2032 battery with the positive side toward the cap. Then screw the cap back on till it is tight and the optic is ready to go. If you plan on using the sight in a co-witness fashion with iron sights, simply adjust the red dot till it is in line with the rear and front sight. If you do not have iron sights installed on your rifle, zeroing the optic is still very simple. In much the same way that you would adjust the zero on any other optic, simply remove the elevation and windage caps and use a screwdriver, or the cap to make the appropriate adjustments in the X and Y axis. These adjustments come in 0.5 MOA increments, so a precise zero is obtainable.

This is the view through the ROMEO5 in the middle of the day on the 6th power setting.

I guess I am backtracking here, but turning the ROMEO5 red dot on is extremely simple and intuitive. Once the battery is installed, all you have to do is press the “+” symbol on the top and it will power on. In order to adjust the brightness down or up, you just press the “-” and “+” symbol respectively.


As you can probably tell by now, I am very happy with the performance of the Sig Sauer ROMEO5 compact red dot. It held zero despite taking the abuse of the powerful 450 Bushmaster round. The optic is crisp and clear from edge to edge. The red dot is adjustable through a large brightness range and is bright enough to be seen in the brightest direct sunlight. Coupled with a lithium battery and the MOTAC system, battery life is incredible and of course, I have not had to change it yet. Sighting in the ROMEO5 was easy as well as installation. Because of the infinite eye relief of the ROMEO5, I was able to place this optic anywhere on my rifle based on my preferences. In the end, this is an optic that I will buy another of and would definitely recommend to a friend.

The 1.41-inch riser that is included with the ROMEO5 is solid and lightweight.


  • 2 MOA dot
  • 1x magnification
  • 20mm aperture
  • 8 day & 2-night vision illumination settings
  • 40 MOA minimum of elevation and windage adjustment
  • Only 5.1 ounces with the 1.41” riser
  • Waterproof with an IPX-7 rating
  • Comes in 5 different models which include 3 different reticle offerings and 2 different battery styles.
  • MSRP of $179 – $359 depending on the model


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About the author: Riley Baxter is an avid and experienced hunter, shooter, outdoorsman, and he’s worked in the backcountry guiding for an outfitter. He also get’s a lot of enjoyment out of building or customizing his firearms and equipment. Check out Riley’s Instagram @Shooter300

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  • johnnyraygun June 11, 2019, 1:51 pm

    I am not sure why I am answering this question, but what the hell.
    Yes there is a way,,,,,,,, google” 1911 red dot mount” and you will see your options. The best way is to remove your rear sight and buy a mount designed to fit in the dovetail slot. The accuracy is based on the amount of movement in your slide. Sig makes a quality 1911, but all 1911’s have some slide movement.

    Burris fast fire II works great for your needs and they have a no questions asked lifetime return policy. I have returned one and their service is excellent.

  • Rod Arnold June 11, 2019, 12:17 am

    I have a Sig SS 1911 with the bottom rail. I’ve been thinking of putting a reflex or red dot on this pistol. Is it possible to do this?

    Rod Arnold

  • Bob June 10, 2019, 12:25 pm

    I picked one up for $119 and it’s well worth that. the dot doesn’t move if you move your head like some of the cheaper ones. it stays zeroed and is easy to sight in. In bright sunlight it can take a little getting used to but overall it’s great. Especially for what I’ve got in it.

  • The professor June 10, 2019, 9:02 am

    Ummm. All red dot 1x scopes are parallax free… That’s literally the point of them. Smh

    • AJ June 13, 2019, 8:01 pm

      Some cheaper ones claim to be but do have a slight parallax. Not all sights are made the same, and not all manufacturers like to admit when they sell a subpar product.

  • LL June 10, 2019, 8:32 am

    I have one on my Springfield SAINT Edge 556. I love it and got it for FAR less than the $179.00 msrp.

  • johnnyraygun June 10, 2019, 8:28 am

    This and many other red dots are strangely similar to Holosun red dots. So if you like the Sig, but not the price, buy a Holosun and your getting the same thing, maybe less a few bucks.

  • Greg June 10, 2019, 5:49 am

    I have one on my PCC. Very fast to acquire, and very accurate. The housing is thin enough to not interfere with transitions. I like it

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