Blog

Guides, comparisons, and findings from the dataset. Plain answers to which red dot fits what, and why.

• Sig P365 Red Dot Compatibility: What Fits the X, XL, X-Macro and Fuse

  August 13, 2026 · 3 min read

  The P365 line looks like a compatibility maze. It is not. Every optic-ready P365 in our data shares one footprint, and most fit the same 40 red dots.

• Holosun 507C: What Pistols Fit It, Directly and With a Plate

  August 6, 2026 · 3 min read

  The Holosun 507C uses the RMR footprint, so 7 pistols take it directly and 110 more fit with a plate. Here is the full breakdown.

• Ruger RXM Optic Compatibility: 95 Red Dots, Zero Adapter Plates

  July 30, 2026 · 4 min read

  Every optic that fits the Ruger RXM in our data mounts direct, no plate. 95 red dots across three footprints. Here is the full breakdown.

• The RMSc Footprint Explained: Which Optics and Pistols Use It

  July 23, 2026 · 3 min read

  The RMSc is the footprint carry pistols are built around. 80 are cut for it directly, and 32 optics from 11 brands fit the pattern. Here is what works.

• Glock 19 Gen 5 MOS Red Dot Compatibility: Every Optic That Fits, Verified

  July 19, 2026 · 3 min read

  The Glock 19 Gen 5 MOS fits 101 red dots in our data. Only one mounts directly. The other 100 need an MOS plate. Here is how it actually works.

• The RMR Footprint Explained: What Fits It and What Doesn't

  July 19, 2026 · 3 min read

  The RMR is Trijicon's mounting pattern, and 47 optics from seven brands use it. But only 7 pistols are cut for it. Here is what actually fits.

• Do You Need an Adapter Plate? A Plain English Guide to Pistol Optic Footprints

  June 25, 2026 · 6 min read

  Sometimes yes, sometimes no. It comes down to one thing: whether your slide's cut matches your optic's footprint. Here is how to check yours.

• We Mapped 134 Optics to 11 Footprints. Here Is What We Found.

  June 25, 2026 · 7 min read

  We mapped every pistol red dot to the footprint it mounts on, with a source on each fit. 134 optics, 11 footprints, 196 pistols. The optic market and the pistol market do not agree.