How to Mount a Riton Red Dot on a Ruger-5.7 By: David Freeman

Ruger-5.7 pistol with a Riton MPRD red dot sight atop a yellow bullseye target

I was jealous of my son’s FN Five-seveN pistol, but the price of that gun kept my obtaining one out of reach. Then, Ruger entered the 5.7 market with a pistol that was more affordable. The Ruger-5.7 is chambered in the high-performance and low-recoiling 5.7x28mm caliber with all the features a guy could want in such a gun. It’s a big pistol, but lightweight at only 24.5 ounces. The overall length of the gun is 8.65 inches with a barrel length just shy of 5 inches. The height is 5.6 inches, and the width is 1.2 inches. The Ruger-5.7’s capacity is 20+1.

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The frame is glass-filled nylon, but the slide is hardened, billet steel with lightening cuts. It is drilled and tapped for easy mounting of optics with a separately available optic adapter plate. I got my 5.7 during the red dot craze, which may not be over yet, but at the time certainly put the desire in me to add a red dot sight to my new favorite pistol.

Rear quaretering view of the Riton Tactix MPRD mounted on a Ruger-5.7 handgun
The Riton Tactix MPRD sight complements the Ruger-5.7 nicely.

When it comes to mounting a red dot to a pistol, there’s an easy way and there’s a creative way. The easy way is to find a sight and mount recommended by the manufacturer and offered through the company’s sales channels. In the case of Ruger, a visit to provided several options making the easy way something to consider. The easy way was also the more expensive way which is why the creative way was for me the more viable option. My budget for guns and accessories competes with the household budget for access to a limited amount of funds.


Finding The Right Solution

The Ruger-5.7 slide has pre-drilled optic mounting holes just ahead of the rear sight. Two mounting plates designed to fit those holes from Ruger. One of the available mounts fits Burris and Vortex red dot sights. The other fits Docter, Meopta, EOTech and Insight sights. At the time of my project, Ruger offered the Vortex Viper and Venom red dot sights. Ruger still does, but today there are lower cost options.


One of the Vortex sights would have been my choice for the easy way. Since I was taking the more economical way, and of course creative way, I found a Riton Tactix MPRD 3 MOA red dot that used the Venom red dot footprint. I ordered the appropriate mount and figured I was all set to go.

Oops! A Problem

The next step in my adventure would have occurred whether I had chosen the easy way or the creative way. I could not remove the set screws filling the pre-drilled holes on the Ruger-5.7’s slide. They were either cross-threaded or had been put in using something like a permanent blend of Loc-Tite. When my Allen wrench began to round out the holes instead of loosening the screws, I stopped trying and considered two options.

I could either drill out the screws and risk damaging the threads, or I had to call Ruger customer service and arrange to send the slide to them to have the screws removed. Choosing the second option allowed me to experience the amazing customer service offered by Ruger. The call went to Ruger’s Prescott, Arizona facility and was answered promptly.

Red dot mounting holes on the Ruger-5.7 handgun
The Ruger-5.7 has pre-drilled mounting holes for a red dot sight.

From the first words of the call, I began to think of the customer service rep as a friend who was there to help me — and help me, she did. She issued me a workorder number to use when sending the slide to Ruger. I did via Priority Mail. In just a few days, I got my slide back, or maybe it was a replacement, with set screws that were easily removed. Since the slide is not serialized, I’m not sure if it was the original slide or a different one.

Mounting Challenges

When it came time to mount the Riton red dot to the mounting plate, the threads on the screws that came with the sight didn’t fit the holes in the mounting plate. Many moons ago, I attended the Army’s Aircraft Maintenance Officer course where I took a class on thread sizes and nomenclature, so I understood the issue.

I have a nice collection of machine screws in all the popular sizes for mounting optics, all the way from 4-40 through common thread sizes such as 6-40, 6-48, 8-40, etc., but none of them would fit. A quick call to Ruger got my original customer service rep on the phone. I asked her about the thread sizes in the mounting plate. I heard her turn around and ask a tech who told her the holes were threaded for M3 screws. Hmmm, Ruger has gone metric.

Red dot mounting plate has red dot sight mounts for the Ruger-5.7 and several popular red dot sights.

If you’re going to fool around with accessorizing guns, get yourself a kit with an assortment of small screws of various types and with metric sizes. I located an M3 Hex Socket Button Head Cap Screw set by iexcell with 250 pieces. I figured I’d have the metric small screw issue covered for a while, and the cost was less than $10. Two M3x10 screws from the kit worked perfectly as replacements for the mounting screws that came with the Riton sight.

Time To Sight It In

With the Riton Tactix MPRD mounted, the next step was to sight the red dot in. Although I have several laser bore sighters that fit inside the barrel of different calibers, I find myself most often going to the Firefield Red Laser Universal Boresight. This model sticks magnetically to the muzzle of any firearm and projects a red laser beam. The beam is an accurate indication of where a projectile would travel from that firearm.

Sighting in the ADE red dot was a simple task of aligning its red dot with the red dot from the laser at a particular distance. I chose 15 yards for two reasons. First, if a red dot is on target at 15 yards, it’s going to be on target at the reduced yardage that would likely be in a self-defense situation. Second, that’s the longest distance I can manage at home sighting against my garage’s back wall.

Firefield magnetic boresighter
The author used the Firefield magnetic boresighter to align the red dot sight before going to the range.

Riton included a small Allen wrench with the sight that fits the adjustment screws. The windage adjustment screw is on the right side of the sight. The height adjustment screw is on the top near the back. The adjustments were easily made to bring the two red dots in alignment.

Shooting the Ruger-5.7 is a hoot, no matter how you slice it. Checking the alignment of a new red dot sight is just icing on the cake. Here’s where I would normally tell you about all the different types of ammo I used, which ones grouped the tightest, and how they all worked well in the gun. However, there are only two types of 5.7×28 ammo available on the planet right now. One is a 40-grain JHP from Federal, and the other is the 27-grain lead free from FNH USA. The latter is labeled: “For Law Enforcement and Military Use Only,” but there’s no law prohibiting the sale to individuals.



Range Time

The Riton red dot sight is a 3 MOA sight with a ‘Shake Awake’ feature that saves battery life but ensures the sight is ready when you aim the gun. I checked alignment of the red dot sight using both the Federal 40-grain FMJ ammo and FNH 27-grain ammo. I found the results very satisfying and oh so much fun. If the ammo was not so expensive, I could shoot this gun all day. Having a red dot sight on it makes it even more fun.

The 3 Tactix MPRD 2 is an extremely compact and versatile pistol red dot with Shake Awake, auto brightness, and auto off after 3 minutes with no motion. It accepts one CR2032 battery and has a 50,000-hour battery life, with a 3 MOA dot and a 1 MOA windage and elevation adjustment.

Adjustment screws on the Riton MPRD red dot sight
Adjustment screws on the Riton MPRD sight are handy. The sight adjusts the dot in 1 MOA increments.

Final Thoughts

I predict the time coming when red dot sights will be as common on our carry pistols as scopes are on deer rifles. It’s true, they present some challenges as far as holstering and concealment go, but they sure do add to the ability to get on target quickly. That’s especially true for us older guys with hand and eye issues that we didn’t have when we first started shooting. If you’ve not yet taken the plunge, there are red dot sights available at prices that make it a no-brainer.

Are you a fan of red dot sights? Do you run a red dot on your carry gun? What do you think about topping a Ruger-5.7 with a red dot? Share your answers in the comment section.