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Red dot footprints and why they differ
Red dot footprints are the bolt-and-recoil-lug pattern on the base of an optic, and they are not interchangeable between families.
What a footprint is
A footprint is the specific arrangement of mounting screws, locating pins and recoil bosses on the underside of a micro red dot. It determines which mounting plate or slide cut the optic will bolt to. Because each family placed those features differently, a plate machined for one footprint will not line up with another.
This is the single most common mounting error with pistol and rifle red dots: assuming any small optic bolts to any plate.
The common patterns
The widely seen footprints include Trijicon RMR, Docter/Noblex, Shield RMS and RMSc, Aimpoint ACRO, Aimpoint Micro (T-1 and T-2), and Leupold DeltaPoint Pro (DPP). Holosun optics are made to either the RMR or the RMSc pattern depending on the model, which is why a Holosun can share a plate with those families.
Each of these has its own hole positions and locating features, so they are genuinely distinct standards rather than minor variations.
Why they are not interchangeable
The RMR footprint uses a pair of screws with locating bosses in one arrangement; the DeltaPoint Pro uses a different pattern; the Aimpoint ACRO clamps to its own dovetail-style interface entirely. Bolt an RMR-pattern optic to a DPP-cut slide and the holes simply do not align, and forcing it risks stripping threads or leaving the optic unsupported against recoil.
The safe path is to identify your optic's footprint, then buy a plate or slide cut for that exact footprint and your rail or slide.
| Footprint | Notes |
|---|---|
| Trijicon RMR | Very common; Holosun RMR-pattern models match |
| Aimpoint ACRO | Own dovetail-style interface |
| Aimpoint Micro T-1/T-2 | Micro-mount pattern |
| Shield RMSc | Compact; Holosun RMSc-pattern models match |
| Leupold DeltaPoint Pro | Distinct hole pattern |
| Docter / Noblex | Long-standing European pattern |
Common red dot footprints and how they relate
Choosing a plate
Work from the optic to the plate to the rail. First name the optic's footprint, then choose an adapter plate that is cut for that footprint on the optic side and Picatinny (or your slide cut) on the mounting side. Confirm both halves before buying, because a plate that is right for the rail but wrong for the footprint is useless.
Match your red dot to the right plate
Open the rail and mount finderSelect your optic footprint and rail to find a plate that fits.Find RMR footprint picatinny adapter plate on eBayaffiliateRelated
Sources: Trijicon ยท Aimpoint