Sig Sauer Romeo 5 vs Romeo 4 Scope Comparison 2021

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By Dennis Howard •  13 min read

Sig Sauer builds great firearms.  There is no question about that. Sig Sauer also builds fine optics.  There is no doubt about that either.  For anyone looking for a compact red dot scope, the Sig Sauer Romeo line of scopes may be an answer.  The question may boil down to which is better for you, the Romeo 4 or Romeo 5 scope?

You won’t go wrong choosing a Sig Sauer scope, no matter which variety or model.  Sig builds excellent optics with a range of features to suit any shooter.  However, when it gets down to choosing models, it can be a confusing situation. 

There are no cut and dry answers to which scope you should choose.  The most basic question to answer is, does the scope fit your needs and deliver your expectations?  You should choose your scope based on those qualifications.

In this case, we are looking at the Sig Sauer Romeo 4 vs Romeo 5 red dot scopes.  The Romeo4 and Romeo 5 optics sit in the mid-range of Sig Sauers red dot sight lineup.  While surprisingly similar on the surface, when these two scopes go side by side, you find some interesting differences that could affect your scope purchasing decision.

  • The solar power features extend battery life.
  • The Romeo line is a feature-rich line of red dot optics.
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  • A less expensive option than the Romeo4 for those on a budget.
  • Includes a Picatinny rail adapter.
  • Multiple battery options.
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Sig Sauer Romeo 4 – Bringing Sunshine into the Mix

Sig Sauer Romeo4S

One of the problems with many red dot sights is battery life.  Being what they are, red dot sights depend on a power source to illuminate the red dot reticle.  If the battery dies, in most cases, the red dot scope is useless.  Keeping your scope running and operable makes the discussion of battery life on a red dot scope a focus for many shooters.

The job of any scope is to gather light and transmit that light to the shooter’s eye.  Sig Sauer has taken the concept of gathering light a step further.  The Sig Sauer Romer 4 incorporates a small solar cell array on the scope that extends the battery life.  Under the right conditions and uses, this solar capability can double the standard battery life on a Sig Sauer Romeo 4 to 100,000 hours.

Sig Sauer Romeo5

The Romeo5 red dot sight doesn’t include the solar cell technology of the Romeo4 sight.  What you do get is options on the battery style that powers your Romeo5 red dot sight.  The Romeo5Dr and the Romeo5X use AAA batteries.  A standard CR2032 battery powers the Romero5 in a side-loading configuration for quick and easy battery changes. 

Speaking of Sub-Models – Subtle Differences Are Important

Each of the Sig Sauer further identifies its Romeo4 and Romeo5 red dot scopes by sub-categories.  These sub-categories identify other small features and details included as part of the red dot scope package.  Looking at the sub-categories for each model and the different features can give you a much better feel for which scope will meet your needs in the long run.

The Sig Sauer website only lists three sub-models as of the writing of this article.  The three models of the Romeo4 optic.  However, each sub-model has further options.  These other differences bring the total model choices to seven.

Model IdentificationPower SourceReticle SelectionObjective Lens Size
Romeo4HBattery Only1 MOA Plex 2 MOA Dot + 65 MOA Circle + BDC30MM
Romeo4SBattery + Solar1 MOA Plex 2 MOA Dot + 65 MOA Circle + BDC20MM
Romeo4TBattery + Solar1 MOA Plex 2 MOA Dot + 65 MOA Circle + BDC20MM
Romeo5XDRBattery OnlyCircle Dot Dual Reticle20MM
Romeo5XBattery Only2 MOA Red Dot20 MM
Romeo5 (high mount only)Battery Only2 MOA Red Dot20 MM
Romeo5 TREADBattery Only2 MOA Red Dot20 MM
Romeo5AAA or CR2032 depending on sub-model2 MOA Red Dot20 MM

The Question of Aiming and Dot Size

When aiming with a red dot sight, the dot’s size can often be a critical element in accuracy.  A 2 MOA red dot will appear to cover 2 inches of your target at 100 yards.  If we assume that 100 yards is about the maximum distance anyone shoots a rifle equipped with a red dot sight, you can understand the significance a 2 MOA red dot can have on accuracy.

Getting your Romeo red dot sight to zero is critical.  The reticle’s travel with each click of the turret and the total travel gives an idea of how well you can adjust the red dot sight for accuracy.

ModelDot SizeTravel per ClickTotal Windage AdjustmentTotal Elevation Adjustment
Romeo4H2 MOA0.5 MOA100 MOA @ 100 yds100 MOS 2 100 Yds
Romeo4S1 or 2 MOA0.5 MOA100 MOA @ 100 yds100 MOA @ 100 yds
Romeo4T2 MOA0.5 MOA100 MOA @ 100 yds100 MOA @ 100 yds
Romeo5XDR2 MOA1.0 MOA100 MOA @ 100 yds100 MOA @ 100 yds
Romeo5X2 MOA1.0 MOA100 MOA @ 100 yds100 MOA @ 100 yds
Romeo5 (high mount only)2 MOA1.0 MOA100 MOA @ 100 yds100 MOA @ 100 yds
Romeo5 TREAD2 MOA1.0 MOA100 MOA @ 100 yds100 MOA @ 100 yds
Romeo52 MOA1.0 MOA100 MOA @ 100 yds100 MOA @ 100 yds

Reticle Style and Battery– A Personal Preference to be Considered

The style of reticle you prefer in a red dot sight is purely a personal preference.  Many shooters prefer a single red dot while others find that a circle or holds on the reticle allows faster target acquisition.   In any case, Sig Sauer makes it possible for a shooter to find the right combination of a dot, circle, holds to fit their preference.

The Differences in Reticles

To eliminate any confusion, a quick rundown of each of the different components of a red dot reticle available on Sig Sauer Romer sights may be useful. 

Other Reticle Considerations

There are other considerations when choosing the style of the reticle in a red dot sight.  Illumination and night vision compatibility is important for some shooters, as is the number of illumination intensity settings.  Battery life also plays a role in reticle selection.

ModelReticle ColorsIllumination SettingsBatteryBattery Life
Romeo4HGreen or Red10 daytime/2 NVCR203250,000 Hours
Romeo4SRed10 Daytime/2 NvCR2032100,000 Hours
Romeo4TRed10 Daytime/2 NVCR2032100,000 Hours
Romeo5XDRRed8 Daytime/2 NVAAA50,000 Hours
Romeo5XRed8 Daytime/ 2 NVAAA50,000 Hours
Romeo5 (high mount only)Red8 Daytime/2 NVCR203240,000 Hours
Romeo5 TREADRed8 Daytime/2 NVCr203240,000 Hours
Romeo5Red8 Daytime/2 NVAAA or CR2032AAA – 50,000 hrs. Cr2032 – 40,000 hrs.

MOTAC – Motion Activated Illumination

One of the keys to long battery life in the Sig Sauer Romeo4 and Romeo5 red dot sights is the MOTAC battery management system.   Simple in concept, the MOTAC system constantly monitors the status of your rifle.  If the rifle is at rest and quiet, the MOTAC system powers down the Romeo red dot sight.  At the first movement, the Romeo red dot sight is activated and ready for use.

The MOTAC system is especially effective in those Romeo models that use AAA batteries for power.  AAA batteries have a reputation for short life when used in optical systems.  The MOTAC system helps prolong the life of AAA batteries.  The cutting edge technology of the MOTAC system also ensures that the red dot will be there and ready before you get your rifle to your shoulder.

The Specification Side for the Technically Inclined

Some more technically inclined shooters want to understand the technical specifications of any product they purchase.  There is some truth to wanting this information at your disposal when trying to make final decisions about which optic is right for you.  Because the Sig Sauer Romeo line of scopes share so many features, the technical specifications are close in many places.

Weight7.6 oz7.6 oz7.6 oz5.6 oz5.6 oz5.1 oz5.1 oz5.6 oz

What’s on the Street About the Romeo 4 and 5 Red Dot Scopes

Other users are sources of valuable information about the quality, features, and optics performance in general.  Listening to other users is particularly valuable when it comes to satisfaction with a product.  Every product has its supports and detractors. 

The Sig Sauer Romeo4 Line – The Pros

The Sig Sauer Romeo4 Line – The Cons

  • The solar power features extend battery life.
  • The Romeo line is a feature-rich line of red dot optics.
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Sig Sauer Romeo5 – Pros

Sig Sauer Romeo5 – Cons

  • A less expensive option than the Romeo4 for those on a budget.
  • Includes a Picatinny rail adapter.
  • Multiple battery options.
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Frequently Asked Questions

Is SIG Romeo made by Holosun?

Even though SIG Romeo is their own company, some of their products are actually produced by another company, and that company is Holosun.

The SIG Romeo 5 sight for guns is actually produced in the Holosun factory that is owned by Chinese company Holosun. So all of the SIG Romeo 5 models that are sold on the market are actually manufactured by Holosun.

However, a lot of people don’t actually know this as Holosun isn’t acknowledged in the packaging or selling of the SIG Romeo 5. Even though the sight is produced by Holosun, it is printed with the SIG Sauer logo labelled on it, so you will not know any difference.

So if you want the same features as the Holosun models but don’t want to buy from this company then the SIG Romeo 5 is made with the same features.

Is the SIG Romeo 5 parallax free?

Yes, the SIG Romeo 5 is parallax free. This device is produced by Holosun and sold under the SIG name, and it is completely parallax free.

This means that when the SIG Romeo 5 sight is on a target, and you move your head around, the reticle of the sight will not move with you. Traditionally this would have been a strange feature, but now it is very common for gun sights to be parallax free.

The SIG Romeo 5 is a red dot sight, just like many gun sights are. Generally speaking, any sight that is part of the ‘red dot’ group will be parallax free. Red dot sights also tend to make up the majority of the reflex sight group, so the majority of these sights will also be parallax free.

Generally speaking, parallax free sights are easier to use which is one of the main reasons why the SIG Romeo 5 is such a popular sight.

The Final Opinion

You won’t go wrong choosing either of the red dot optics for your rifle, shotgun, or pistol.   The Romeo4 and Romeo5 are both fine optical systems.  Personal preference becomes a huge factor when two optical systems like the Sig Sauer Romeo 4 and Romeo 5 come so close in so many ways yet offer such significant differences in their features.

Your preference may be in longer battery life.  The solar power capacity of the Romeo4 line will certainly be attractive if battery life is an issue for you.  The choice of battery style may also make a difference.

Reticle choice is primary for some shooters.  Having the style of reticle you prefer to shoot and that matches the shooting you do makes an important part of your decision.

Finally, is the price.  The more features you want and the level of technology these features require almost always translate back to the red dot optic cost.  Deciding on the compromise of cost and features is almost always one of the most difficult decisions.

My Final Choice

In the end, my choice of Romeo4 and Romeo5 models is the Romeo4S.  For me, the exceptional battery life, coupled with the solar charging capability and the available 1 MOA Plex reticle option, stands out.  The Romer4S is one of the more expensive models in the Romeo4 and Romeo5 line, but I think the cost difference is more than worth what you get.

I hope that this review of the Sig Sauer Romer4 and Romeo5 red dot models helps you as you make your decision about which optic to mount on your firearm.  If you have any further information, experience, or would just like to share your thoughts, please leave a comment in the section below.  Sharing knowledge is the idea, and everyone benefits from what you share. Be safe and shoot well.

Dennis Howard

A life long hunter, fisherman, and outdoorsman, after surviving a devastating tornado in his home town, he saw the effects on people's lives as they struggled to cope. He built his first bugout bag a few weeks later and has been a dedicated prepper/survivalist since that time. After a career as a fireman, Dennis opened a retail store (FFL approved) catering to the military, law enforcement, and like-minded individuals. The store built their own AR platforms. Furthermore, Dennis was also an NRA instructor in both long gun and handgun as well as a certified range safety officer. Read his full interview here.