Posted by DUTYTAC on Oct 14th 2026
Pistol Red Dot Footprints Explained: RMR, RMSc, ACRO, DeltaPoint Pro and More
Buyer's guide
Match the pattern, not the brand
The footprint is the screw and recoil-lug pattern under your optic. Match it to your slide cut or plate and the dot bolts right on. Get it wrong and it will not mount.
The 5 footprints you will see most
RMR
The most common full-size pattern. Trijicon RMR and SRO, plus Holosun 407C, 507C, 508T and 507 Comp.
Shop RMR footprint →
Shop RMR footprint →
RMSc / Holosun K
Small pattern for slim carry guns like the Glock 43X/48, Sig P365 and S&W Shield. Holosun 407K, 507K and EPS Carry.
Shop RMSc / K →
Shop RMSc / K →
DeltaPoint Pro
Leupold DeltaPoint Pro and Sig Romeo1 Pro share it. Big window, popular in competition.
Shop DPP footprint →
Shop DPP footprint →
Aimpoint ACRO
Fully enclosed emitter that rain and lint cannot block. A favorite for duty guns.
Shop ACRO footprint →
Shop ACRO footprint →
Holosun 509
Holosun 509T enclosed titanium dot with its own pattern.
Shop 509 footprint →
Shop 509 footprint →
Quick fit chart
| Footprint | Common optics | Typical pistols | Best for |
|---|---|---|---|
| RMR | Trijicon RMR, SRO; Holosun 407C / 507C / 508T | Glock MOS, M&P 2.0 CORE, full-size slides | Duty, home defense, widest optic choice |
| RMSc / K | Shield RMSc, Holosun 407K / 507K, EPS Carry | Glock 43X/48, Sig P365, S&W Shield | Concealed carry |
| DeltaPoint Pro | Leupold DPP, Sig Romeo1 Pro | Full-size and competition slides | Competition, big window |
| ACRO | Aimpoint ACRO | Duty pistols with an ACRO cut or plate | Duty, bad weather |
| 509 | Holosun 509T | Pistols with a 509 cut or plate | Enclosed-emitter duty setup |
RMR footprint optics
RMSc / K footprint optics
DeltaPoint Pro and 509 footprint optics
Plate or direct milling?
Optics-ready pistols use adapter plates. Plates work, but they add height and another set of screws that can loosen. A direct milled cut sits the optic lower, which helps you co-witness with taller iron sights and keeps the setup simpler.
Adapter plate
No machining and easy to swap optics. Sits higher and adds a screw joint.
Shop optics by footprint →
Shop optics by footprint →
Direct milled cut
Lowest height, fewest parts and a tight fit for one footprint.
See optic cuts →
See optic cuts →
How to choose in 4 steps
- Use: duty, everyday carry or competition.
- Size: pick an optic that fits your slide width.
- Footprint: match it to your slide cut, plate or the cut you plan to order.
- Iron sights: suppressor-height sights let you co-witness through the window.
Key takeaways
- Footprint, not brand, decides whether an optic fits your slide.
- RMR is the most common full-size pattern; RMSc / K is the common carry pattern.
- Direct milling sits the dot lowest; plates are easier to swap.
Not optics ready? We mill your slide for the footprint you choose, install the optic with witness marks and bore sight it for free with a complete slide.
See optic cut services →