There is no standard mounting platform for pistol sights. Unlike optics which are purpose-built for rifles, which are almost always compatible with picatinny/M1918 mil-std mounts, a pistol user must pay careful attention to his pistol’s particular red dot footprint. The only way one can force an incompatible red dot onto a pistol is with an adapter, which will raise the red dot’s point of aim even higher, impacting accuracy.
Sightmark’s pistol red dot sights are built on four different footprints for maximum compatibility. This guide is meant for firearm owners who buy their pistol and walk out of the gun show or shop without asking “what kind of red dot footprint to I have?”
This is not a typo. Docter is spelled with an “e,” since it’s named after Bernhard Docter of Docter Optics, which was later acquired by the Noblex company. This is not, nor has it ever been named after a “Dr. Noblex.” The Docter/Noblex footprint is one of the most common mounting standards in the modern shooting world thanks to the stability of the platform. Distinguished by its two central holes for screws and four holes for pins, on Sightmark products this footprint is featured on the Mini Shot M-Spec and Mini Shot Pro-Spec red dot sights.
This red dot mounting standard is distinguished by two sockets for pins and two holes for screws to the rear. This red dot footprint is reserved for fairly large optics such as the Mini Shot M-Spec M2 Solar. RMR stands for “Ruggedized Miniature Reflex Sight” and was originally a proprietary mounting standard for a Trijicon product of the same name, which was designed to replace the Docter Optic Red Dot Sight.
Originally developed by Shield Sights, this mounting standard was designed for their “Reflex Mini Sight” which was a small, low profile red dot optic. One of the smallest red dot footprints, it looks similar to the Docter/Noblex sight with its two screw holes and four sockets, except that the RMS’s screw holes are closer to the rearward sockets than their Docter/Noblex counterpart. This red dot footprint and its even smaller variant, the RMSc (Reflex Mini Sight: Compact) are usually found on compact pistols. Because of its compact design, this mounting standard is featured on the Mini Shot A-Spec M3 Micro.
Easily identifiable by its four screw holes and central trench for a recoil stop, this red dot footprint was designed by Aimpoint in 2007 for its new, compact and rugged reflex optic. Coincidentally, the Sightmark Wolverine, an outstanding example of a rugged rifle optic with its high recoil tolerance and 1 million hours of battery life, based its mounting platform on this same footprint.
Understanding the red dot footprint of your pistol is crucial to ensure a proper fit and optimal performance. By choosing a red dot sight that matches your firearm's footprint, you can enhance accuracy and reliability during shooting.