The RMR footprint

How to identify an RMR cut without a caliper

Take the cover plate off and look straight down into the milled recess. Two things decide it, in this order.

1. Screw holes: two. They sit on the long axis of the cut, and the optic screws pass down through its body into the slide. That is a screw-through mount. If the optic instead clamps sideways onto a rail-like groove with a single cross bolt, you have an ACRO or Holosun 509T interface, not this one.
2. Recoil bosses: two, both forward. They stand proud of the floor of the cut, ahead of the screw holes. Two is the number that matters. The RMSc, DeltaPoint Pro and Docter patterns all put four bosses at the corners. If you count four, you are not looking at an RMR cut, whatever the screws suggest.

On the optic side the tell is the underside: two through holes and two shallow sockets at the front of the base. The Trijicon RMR Type 2 is the reference part (brownells.com), and the Holosun 507C-X2 is one of the 16 Holosun pages built to the same pattern (holosun.com).

The one case counting will not settle. The Holosun K pattern also uses two screws and two front lugs, because it is a modified RMSc with the rear lugs deleted (holosun.com). Counts alone cannot separate K from RMR. Size does: K is a compact carry pattern and RMR is a full size one, and this dataset keeps them as separate footprints with no cross-compatibility in either direction. If your slide is small enough that a 507K looks proportionate on it, stop counting bosses and check the model against the pistol page.

Pattern and dimensions

What this dataset publishes for the RMR footprint today:

Property	Value	Source
Mounting style	Screw-through	dataset
Mounting screws	2	dataset
Recoil bosses	2, both forward	dataset
Footprint family	Trijicon RMR	dataset
Optics recorded on this pattern	33 pages covering 47 SKUs from 7 brands	dataset
Pistols cut for it from the factory	7 of 196	dataset
Pistols reaching it through a plate	110, over 15 plate systems	dataset

Screw thread size, screw centre spacing, boss diameter and body length are not published here. No manufacturer drawing carrying those figures has been read into the dataset, and no window dimension is recorded for any of the 33 optics on this pattern. The rule on this site is to print a null rather than a guess. Until a drawing is sourced, use the screws that ship with your optic, or the length the optic maker specifies for your slide, and do not infer a thread pitch from a forum post.

Look-alikes that will not interchange

RMR against Docter or Noblex. The classic mix-up, because both are two-screw screw-through patterns of a broadly similar size. The Docter pattern takes four corner sockets, not two front bosses. That is the whole difference and it is absolute: a Burris FastFire (burrisoptics.com) or a Vortex Venom will not sit on an RMR cut. The Docter hub carries the 6 optics on that pattern.

RMR against DeltaPoint Pro. Four corner sockets again, plus a longer body (leupold.com). The DeltaPoint Pro hub carries 15 optics. Two pistols in this dataset are cut for DPP directly, against 7 for RMR, so both patterns are plate-dependent in practice.

RMR against RMSc. Different size class and different boss count. RMSc is the pattern the industry actually mills: 80 of the 196 pistols here are cut for RMSc from the factory against 7 for RMR. RMR wins on optic supply, RMSc wins on slides. The side-by-side is in RMR vs RMSc.

RMR against Holosun K. Covered above. Same counts, different size class.

RMR against MOS, VIS, AOS, OSP, LOPMS and the rest. Those are plate systems, not footprints. A slide marked MOS or OSP has no footprint milled into it at all. The plate decides. See Glock MOS and the plate section further down this page.

The Trijicon RMRcc. This dataset holds no record for it, so this page makes no claim about whether it shares the RMR pattern. Where there is no sourced record, there is no answer here.

Optics that are not RMR but still mount on an RMR cut

This is the part that makes an RMR-cut slide more useful than its 33-optic count suggests, and it is missing from most footprint charts.

Two enclosed emitter Holosun patterns ship in the box with an RMR adapter plate, so an RMR-cut slide can carry them at the cost of some added height over the bore:

• The Holosun 509T uses a tool-less clamp interface with no top-down screw holes of its own, and ships with an RMR plate (holosun.com).
• The full size Holosun EPS does the same (holosun.com). The shorter EPS Carry is a K-pattern optic and ships with an RMSc plate instead, so it sits on the Holosun K hub and not here.

Neither optic is an RMR-pattern optic and neither is counted in the 33 above. Both are reasons to prefer an RMR cut over a narrower one if you are choosing a slide today.

How a plate gets you to RMR

7 pistols in this dataset are cut for RMR at the factory. 110 more take an RMR optic through a plate, across 15 plate systems, with no overlap between the two groups: 117 of the 196 pistols here, or 59.7 percent, can carry an RMR optic one way or the other.

In words, a plate path works like this. The slide is milled for a proprietary interface that is not a footprint at all. A plate drops into that interface and its top face carries a real footprint. Fit the plate that presents RMR and the slide behaves, for optic-buying purposes, like an RMR slide. The plate table for each system lives on that system’s own hub, not here.

The largest paths to RMR, by pistol count:

• Glock MOS, 16 pistols. The factory adapter 01 presents the RMR and SRO pattern (opticsplanet.com). Full size MOS pistols only: the Glock 43X MOS and 48 MOS are cut RMSc despite the name.
• SIG P320 X-series, 16 pistols. A modular adapter presents RMR on the X-series cut (outerimpact.com).
• S&W M&P CORE, 14 pistols. A CORE plate presenting RMR (chpws.com).
• FN 509, 12 pistols. The Low-Profile Optics Mounting System with an RMR plate (chpws.com).
• Beretta APX A1, 10 pistols. The 90-Series and APX A1 optic plate kit (beretta.com).
• Walther PDP 2.0, 10 pistols. The Gen 2 plate (optics-spot.com). The PDP 1.0 plate reaches one more.

Eight further systems present RMR on smaller pistol sets: CZ P-10 OR and HK VP9 OR (chpws.com), Canik METE (outerimpact.com), Taurus TORO (shoptaurus.com), Springfield Echelon VIS (store.springfield-armory.com), Springfield XD OSP (store.springfield-armory.com), Springfield AOS (springfield-armory.com) and the Ruger factory plate (outerimpact.com). Every path and its pistol list is in the plate section further down this page.

A plate costs you height above the bore and one more interface that can loosen. If your slide is cut for RMR directly, that is the better mount.

How to choose an RMR optic

There are no prices on this page and no rankings the data can support. What the data does support:

• Supply is the strongest of any pattern here. 33 of the 100 optic pages in this dataset are on the RMR pattern, covering 47 SKUs, more than any other footprint. The brand spread is narrower than the count suggests, though: Holosun alone accounts for 16 of the 33 pages, then Swampfox 5, Trijicon 4, Meprolight 3, Primary Arms 3, Bushnell 1 and Riton 1. Seven brands against 11 on the RMSc hub.
• Open emitter is the default here, enclosed is the exception. 30 of the 33 are open emitter designs. The 3 enclosed options are the Meprolight MPO PRO-F (meprolight.com), the Primary Arms PLx HTX-1 (primaryarms.com) and the Trijicon RCR, whose enclosed classification rests on a source this dataset has not yet upgraded to a manufacturer page. If you carry appendix or in a pocket, weigh that against the 7 enclosed options on the RMSc pattern, or add an RMR plate optic from the section above.
• Buy the slide before the optic, not after. RMR has the deepest optic list and the shallowest factory support. Only the Ruger RXM and the Shadow Systems MR920 among the seven accept more than one footprint directly, which is what makes them the most flexible RMR-cut slides in the dataset.
• Check the optic page, not the brand. Each optic page lists the pistols it fits and links the source for that claim.

Nothing here is verified against a physical sample. Every fit claim on this page is sourced research, a manufacturer or retailer page recorded against the record it supports, and Trijicon’s own spec pages are not yet among the sources on this pattern. Confirm against your own slide before you spend money.

Where to go next

• The full chart: all optic footprints and plate systems.
• The long form article this hub owns: RMR footprint guide.
• The pattern most likely already on your slide: RMSc footprint guide.
• When your slide is not cut for what you want: do you need an adapter plate?
• The largest single plate path to RMR: Glock 19 Gen5 MOS red dot compatibility.
• The most flexible RMR-cut slide here: Ruger RXM optic compatibility.
• RMR-cut pistols: Ruger RXM, Shadow Systems MR920, Anderson Kiger-9C Pro, Lone Wolf Dusk 19, Tisas PX-9 Gen3 Duty.
• Popular RMR optics: Trijicon RMR Type 2, Trijicon SRO, Holosun 507C-X2, Holosun 508T-X2, Swampfox Kingslayer.