Ruger Mark I, II, III, IV and 22/45 Dual-Footprint Red Dot Mounting Plate – Fits Docter/Noblex and RMSc/K Footprints

Product Description

Upgrade your Ruger Mark-series pistol with this precision-machined red dot mounting plate.

The updated plate now features two separate optic mounting-hole patterns, providing direct compatibility with both:

• Docter/Noblex footprint red dot sights

• RMSc/K footprint red dot sights

The plate attaches to the existing drilled and tapped mounting holes on top of compatible Ruger Mark receivers. It does not install through the rear-sight dovetail, so the factory rear sight can remain installed.

No slide milling or permanent modification is required.

Made from aircraft-grade aluminum with a matte black finish, this mounting plate provides a lightweight, low-profile, and secure platform for a wide selection of compact red dot sights.

New Dual-Footprint Design

This updated version includes an additional set of mounting holes for RMSc/K footprint optics.

The two mounting configurations are:

Docter/Noblex Footprint

Docter/Noblex footprint optics use the corresponding forward mounting-hole pattern and locating features on the plate.

RMSc/K Footprint

RMSc/K footprint optics use the rear set of mounting holes.

Important: RMSc/K footprint optics do not use the locating pins at the front of the plate.

This dual-footprint design gives users significantly more optic choices without requiring a separate adapter plate.

Compatible Ruger Models

This plate fits compatible Ruger Mark-series pistols equipped with the factory-drilled and tapped receiver mounting holes.

Compatible models include:

• Ruger Mark I — must have drilled and tapped mounting holes

• Ruger Mark II — must have drilled and tapped mounting holes

• Ruger Mark II 22/45 — must have drilled and tapped mounting holes

• Ruger Mark III Standard

• Ruger Mark III Bull Barrel

• Ruger Mark III Competition

• Ruger Mark III Hunter

• Ruger Mark III 22/45 Lite

• Ruger Mark III 22/45 Target

• Ruger Mark III 22/45 Threaded Barrel

• Ruger Mark III 22/45 Bull Barrel

• Ruger Mark III 22/45 Hunter

• Ruger Mark IV Standard

• Ruger Mark IV Target

• Ruger Mark IV Hunter

• Ruger Mark IV Competition

• Ruger Mark IV Tactical

• Ruger Mark IV 22/45 Lite

• Ruger Mark IV 22/45 Tactical

Mark I and Mark II Compatibility Notice

Some Ruger Mark I and Mark II models were not factory drilled and tapped.

Before ordering, inspect the top of the receiver and confirm that it has the required factory mounting holes.

Compatible Docter/Noblex Footprint Red Dots

Fits many red dot sights using the Docter/Noblex mounting footprint, including:

ADE Advanced Optics

• ADE RD3-006A Huracan

• ADE RD3-006B Python

• ADE RD3-009 Crusader

• ADE RD3-012 Delta

• ADE RD3-012 PRO

• ADE RD3-013 Bertrillium

• ADE RD3-015 Zantitium

• ADE RD3-015 PRO

• ADE RD3-028

• ADE RD3-028 PRO

Other Compatible Optics

• Vortex Venom

• Vortex Viper

• Vortex Razor

• Burris FastFire 2

• Burris FastFire 3

• Docter Sight C

• Docter Sight 2+

• Docter Sight III

• Docter QUICKsight 5.0 VR

• Noblex Sight G

• Meopta red dot sights with the Docter/Noblex footprint

• EOTech MRDS

• Insight MRDS

• Delta Optical MiniDot

• Delta Optical MiniDot II

• Hawke Reflex 1×25

• Sightmark Mini Shot Pro Spec

• Sightmark Mini Shot M-Spec

• Leica Tempus

• MAKdot 1×25

• Vector Optics SCRD-19II Frenzy 1×17×24

• Creative XP GlassEagle HD

• Vomz Pilad 1×20

Compatibility depends on the optic’s actual mounting footprint, screw spacing, and housing dimensions. Confirm the footprint of your specific optic before installation.

Compatible RMSc/K Footprint Red Dots

The newly added rear mounting-hole pattern supports many RMSc and K-pattern red dot sights, including:

ADE Advanced Optics

• ADE RD3-018 Spike

• ADE RD3-021 Nuwa

• ADE RD3-021 PRO Nuwa PRO

• ADE RD3-021 PRO2

• ADE RD3-030 Apollo

Other Compatible Optics

• JPoint

• Shield RMSc

• Shield SMSc

• Shield RMS2

• Holosun 407K

• Holosun 507K

• SIG Sauer ROMEOZero

• SIG Sauer ROMEO-X Compact, SORX1200 only

• Vortex Defender CCW

• Osight SE Enclosed

• Viridian RFX11

• Sightmark Mini

• Riton MPRD 2

• Riton 3 Tactix MPRD

• Swampfox Sentinel

• Springfield Armory HEX Wasp

• Crimson Trace CTS-1550

• Crimson Trace CTS-1250

• Crimson Trace CT RAD Pro

• Cyelee CAT PRO

• Cyelee CALF V2

Some optics described by manufacturers as “K footprint” may have modified recoil-lug or screw-hole requirements. Confirm the mounting dimensions of your optic before installation.

Important RMSc/K Installation Notice

RMSc/K footprint red dots must be installed using the rear set of optic mounting holes on the plate.

Do not use the locating pins at the front of the plate when installing an RMSc/K footprint optic.

The front locating pins are intended for compatible Docter/Noblex footprint optics.

The absence of front-pin engagement with an RMSc/K optic is normal and is part of the plate’s dual-footprint design.

Installation

1. Confirm that the Ruger receiver has the required drilled and tapped mounting holes.

2. Make sure the pistol is unloaded and follow all manufacturer safety instructions.

3. Position the mounting plate over the factory receiver holes.

4. Select the correct receiver screws and verify that the screw length is appropriate.

5. Secure the plate to the receiver.

6. Identify the correct mounting-hole set for the optic:

   • Use the corresponding Docter/Noblex mounting pattern for Docter-footprint optics.

   • Use the rear mounting holes for RMSc/K footprint optics.

7. Install the optic using the correct screws.

8. Apply a small amount of medium-strength removable threadlocker if recommended.

9. Tighten the screws evenly to the optic manufacturer’s recommended torque specification.

10. Confirm secure installation before use.

Professional installation is recommended if you are unfamiliar with optic mounting or screw-length verification.

Screw-Length Warning

Ruger Mark models and optic housings may require different screw lengths.

A receiver mounting screw that is too long may extend into the receiver and interfere with internal movement. An optic screw that is too long may bottom out before securely clamping the optic.

Before final tightening:

• Confirm that each screw engages the correct threads.

• Confirm that the screw does not bottom out.

• Confirm that receiver screws do not protrude excessively into the receiver.

• Confirm that the optic sits completely flat against the plate.

• Do not force or overtighten any screw.

Stop installation immediately if you feel abnormal resistance.

Key Features

• Updated dual-footprint mounting system

• Fits Docter/Noblex footprint optics

• Fits RMSc/K footprint optics

• Additional rear mounting holes for RMSc/K optics

• Mounts to factory-drilled Ruger receiver holes

• Rear sight can remain installed

• No slide milling required

• No rear-sight dovetail removal required

• Precision CNC-machined construction

• Aircraft-grade aluminum

• Matte black finish

• Low-profile design

• Lightweight and durable

• Mounting hardware and Allen wrench included

Specifications

Compatible platform: Ruger Mark I, Mark II, Mark III, Mark IV and 22/45 models with appropriate receiver mounting holes

Optic footprints:

• Docter/Noblex

• RMSc/K

Material: Aircraft-grade aluminum

Finish: Matte black

Installation type: Factory receiver screw-hole mounting

Rear-sight removal required: No

Permanent modification required: No

Color: Black

Package Includes

• One Ruger Mark-series dual-footprint optic mounting plate

• Receiver mounting screws

• Optic mounting screws

• Allen wrench

Red dot sight is not included.

Important Compatibility Information

This plate is designed around mounting-footprint dimensions. Brand names and model names are provided only as general compatibility references.

Manufacturers may revise an optic’s screw pattern, housing dimensions, recoil-lug configuration, or footprint without notice. Verify your specific optic before installation.

Compatibility with one model from a manufacturer does not guarantee compatibility with every optic made by that manufacturer.

Why Choose the Updated Plate?

The earlier version was designed primarily for Docter/Noblex footprint optics. This updated version adds a second set of mounting holes for RMSc/K footprint red dots.

The dual-footprint design allows one Ruger Mark mounting plate to support a much wider range of popular compact optics while retaining a simple, low-profile installation.

For RMSc/K optics, simply use the rear mounting-hole set and leave the front locating pins unused.