The RMR Footprint Explained: What Fits It and What Doesn't

The RMR footprint is the mounting pattern Trijicon designed for its RMR optic. Two screws, two recoil lug sockets at the front, and that is the whole interface. It became the closest thing the pistol world has to a universal standard, and 47 optics in our data use it, from seven different brands. The catch is on the gun side. Only 7 pistols in the set are cut for the RMR directly. If your slide is not one of them, you mount an RMR optic with a plate.

What is the RMR footprint?

The RMR cut uses two mounting screws and two recoil lug sockets at the front that index the optic to the slide and take the recoil. Trijicon built it for the RMR Type 2, and because the RMR sold so well to police and military buyers, other optic makers copied the pattern so their sights would drop into the same slide cuts, plates, and holsters. That is the short story of how a footprint named after one company’s product became an industry default. The name still belongs to Trijicon, but the pattern is open and everyone builds to it.

Which optics use the RMR footprint?

47 of them, and only 8 are Trijicon. Here is the brand breakdown straight from the data:

• Holosun: 26 optics, the most of any brand. The 407C, 507C, and 508T families all sit on the RMR pattern.
• Trijicon: 8, including the RMR Type 2 line, the newer RMR HD, and the RCR.
• Swampfox: 5, the Justice, Kingslayer, Liberty, and the second-generation versions.
• Meprolight: 3.
• Primary Arms: 3.
• Bushnell and Riton: 1 each.

Holosun making more RMR optics than Trijicon is the part most buying guides skip. If you want an RMR-pattern sight, you are not choosing between a Trijicon and nothing. You have 47 options across a huge price range. The complete list is on the RMR footprint page.

Which pistols are cut for the RMR directly?

Seven, and they have something in common. The Anderson Kiger-9C Pro, both Lone Wolf models (the Dusk 19 and the LTD19 V1), the Ruger RXM, the Shadow Systems MR920, and two Tisas PX9 pistols. Notice what is not on that list. No factory Glock. No Sig. No factory Smith and Wesson. The RMR cut shows up mostly on aftermarket and clone slides built for the Glock platform, where the slide maker chose RMR because the optic selection is so deep. The Ruger RXM is the standout. Its cut is open enough that 95 optics drop straight on with no plate at all.

What if my pistol is not RMR-cut?

Then you use an adapter plate, and most optic-ready pistols can. The plate bolts into your slide’s real cut, usually a Glock MOS or a Sig plate system, and presents an RMR pattern on top. You add a little height and one more part that can work loose, so torque it to the maker’s spec and use thread locker. Done right, it holds zero fine. To see whether your specific pistol takes an RMR optic directly or through a plate, find it on its pistol page and read the listed footprints. The Ruger RXM page is a good example of a direct-cut slide.

The RMR won the optic side of this market years ago. The pistol side never fully agreed, which is why the plate exists. If you are buying an RMR optic, the Holosun 407C and 507C are where most people should start on price and battery life. Go Trijicon, the RMR HD or the RCR, if you want the name and the duty track record behind it. Either way, confirm your slide’s cut before you spend the money.