RMR vs RMSc Footprint: 33 vs 30 Optics, 7 vs 80 Pistols

The RMR and the RMSc are the two footprints with the most optics in our data. 33 optics fit the RMR. 30 fit the RMSc. Past that headline they have almost nothing in common. The RMR is a full-size pattern with the deepest optic support and hardly any pistols cut for it, just 7. The RMSc is a micro pattern with fewer optics but far more slides: 80 of the 196 optic-ready pistols we track are cut for it directly. One footprint owns the optic aisle. The other owns the pistol side.

What is the difference in size?

The two footprints target different guns. The RMSc is the micro pattern. It uses two screws and four corner recoil bosses, and it lives on subcompact and compact carry slides where space is tight. The RMR is the full-size pattern: two screws, two front recoil lug sockets, and a larger body meant for duty and competition pistols.

Same screw count, different footprint. An RMR optic will not sit in an RMSc cut, and an RMSc optic will not sit in an RMR cut. The patterns do not interchange.

One caveat lives in the RMSc data. The same RMSc screw and recoil pattern exists at two physical lengths, a 40mm micro size and a 46mm full size. A slide cut for the 40mm optic will not take the 46mm one. Check the length, not just the footprint name.

How many optics fit each footprint?

33 fit the RMR, 30 fit the RMSc. The RMR wins on count, but the reason is one brand. Holosun alone builds 16 of the 33 RMR optics, close to half. Swampfox builds 5, Trijicon 4, and the rest come from Meprolight, Primary Arms, Bushnell, and Riton.

The RMSc spreads wider. Its 30 optics come from 12 brands, five more than the RMR. Shield Sights leads with 7, then Sig Sauer with 5, then Meprolight and Riton with 3 each, followed by Bushnell, Primary Arms, Swampfox, Vortex, Burris, Crimson Trace, Holosun, and Steiner. So the RMR gives you depth from Holosun. The RMSc gives you more names to choose from at a smaller total.

The full lists live on the RMR footprint page and the RMSc footprint page.

Which pistols are cut for each one?

This is where they flip. The RMSc is the most common cut on the pistol side by a wide margin. 80 of the 196 optic-ready pistols in our data are milled for it directly, more than any other footprint. Most are carry guns: the Sig P365XL and the rest of the P365 family, the Springfield Hellcat, the Canik METE MC9, the S&W Shield Plus, and dozens more small slides where the RMSc is the only pattern that fits.

The RMR goes the other way. Only 7 pistols in the set are cut for it directly, and they are mostly aftermarket or clone slides: the Ruger RXM, the Shadow Systems MR920, two Lone Wolf models, the Anderson Kiger-9C Pro, and two Tisas PX9 pistols. No factory Glock, Sig, or S&W cuts the RMR.

One gun is cut for both. The Ruger RXM accepts the RMSc and the RMR at the slide, the only pistol in our data that takes either footprint with no plate.

Which footprint should you pick?

You do not pick a footprint. Your pistol picks it for you, and this is the part buyers get backwards. They read that the RMR has the most optics, decide they want an RMR sight, then find out their P365 was never cut for it. The slide decides which footprints are open to you, and the optic has to follow.

So start at the gun. If you carry a subcompact, you are almost certainly on the RMSc, and your job is to pick one of its 30 optics. If you run an aftermarket or clone Glock slide, or the Ruger RXM, you may have an RMR cut and all 33 of its optics open to you. If your slide uses a plate system, you can reach either footprint through the right plate.

Look up your exact model on its pistol page. It lists the footprints your slide accepts and marks each optic as a direct fit or a plate fit, with a source on every one. Confirm the cut first, then buy the optic.