Guide to Pistol Red Dot Footprints
Posted by Monstrum on Aug 19th 2026
Must Know Before Buying!
A pistol red dot sight can greatly improve your speed and accuracy when shooting a handgun, but in order to mount one directly to your pistol’s slide, you must first ensure that your red dot sight has a compatible mounting footprint to your pistol’s slide. In this article, we’ll explain what mounting footprints are, describe some of the most common footprints today, and list a few of the more popular red dot sights that use each.
What is a Pistol Red Dot Mounting Footprint?
A pistol red dot mounting footprint is the layout of screw holes and sockets on an optic that correspond to pins on a pistol’s slide for direct mounting. Direct mounting on most modern handguns involves attaching an optic via two screws and usually two or four pins that act as recoil lugs on the slide that mate with recesses on the bottom of the optic. The layout of these screws and sockets vary by optic manufacturers, but most pistol red dot sights made today fall within six footprints: RMR, Shield RMSc, Holosun K, Delta Point Pro, Docter, and Acro. We’ll explain the differences between each in the following sections.
Optics Mounting Adapter Plates
While most “optics ready” pistol slides are milled for one specific mounting footprint, one more popular method for getting around mismatched patterns are optics adapter plates. Adapter plates are thin pieces of metal or plastic that sit between the pistol red dot sight and the pistol slide. They can be used to mount an optic of one pattern onto a slide with another.
While adapter plates are useful for mounting pistol optics to guns that wouldn’t otherwise be able to accept them, they come at the cost of added complexity and deck height. Most pistol red dot sights occlude the sight picture of factory iron sights, so suppressor-height sights are recommended in most cases if you want to be able to co-witness through your red dot.
RMR Mounting Footprint
One of the first modern pistol red dot sights to see widespread military adoption was the Trijicon RMR, and the pattern of screw holes that this pistol red dot used is called the RMR footprint. The RMR footprint consists of two screw holes apart and two recoil lugs in the front corners. This pattern is one of the most popular optic mounting footprints for full-sized and compact handguns.
Some red dot sights that use the RMR footprint include:
Trijicon RMR
Trijicon SRO
Holosun 507C X2
Holosun 407C X2
Swampfox Kingslayer
Swampfox Justice II
Monstrum Nitro+
Monstrum B.O.P.
Shield RMSc Mounting Footprint
The Shield RMSc pattern is the most popular mounting footprint among smaller sub-compact and micro compact pistols. It was developed by Shield Sights in 2018 and uses two screw holes and four pins.
Popular optics that use this footprint include:
Vortex Defender CCW
Swampfox Sentinel II
Sig Sauer Romeo Zero
Monstrum Nitro and Nitro+
Holosun K Mounting Footprint
The Holosun K is derived from the Shield RMSc pattern. This footprint has two screw holes and two pins at the front corners, though both of these fall in the same position as they do with Shield RMSc. The only differences are that the Holosun K footprint lacks the two rear pins and the front two are cut shorter than they are on the RMSc pattern. This means optics made for the RMSc pattern can mount to the Holosun K footprint, but optics with the Holosun K footprint can’t mount to RMSc pattern slides.
Popular optics that use this pattern include:
Holosun 407K X2
Holosun 507K
Holosun EPS
Holosun EPS Carry