Ruger Mk. iii/iv Co-Witness Mount Installation Instructions

Make sure all parts are included. Use the table below to take inventory. If the inventory does not include screws to attach your optic to the mount, please use the screws that came with your optic.

Make sure your pistol is unloaded and safe before continuing.

If you have the Aimpoint Micro mount, please see the additional notes here, then come back here to finish the installation instructions: Aimpoint Micro Mount

Remove your front sight by removing the screw holding it in place. This screw will be re-used, hang on to it.

Remove your rear sight by loosening the set screw in the top, and drifting it from left to right.

Install the rear sight onto the mount by pressing it into the dovetail from right to left. There is an arrow engraved in the mount to indicate the correct direction. Center the sight in the dovetail. Lock the sight in place by tightening the set screw in the top of the sight.

Install the new front sight using the original screw. Do not exceed 5 in-lbs!

Install your optic onto the mount. Use the table below for torque values, make sure not to exceed those values! Then make sure the screws do not protrude below the bottom of the mount, as shown in the picture below.

Install your optic and mount onto your pistol.Do not exceed 7 in-lbs!

Perform a function check and make sure the pistol is safe to fire.

Sight in the irons using the adjustable rear sight as you normally would.

Optics footprintInventoryOptic Screw Torque Value
Aimpoint AcroOptics mount
Front Sight
2x mount mounting screws (6-48 flat head, torx drive screws)
See optic manufacturers instructions
Aimpoint Micro
See additional instructions here
Optics mount
Front Sight
2x mount mounting screws (6-48 flat head, torx drive screws)
4x M3 mount mounting screws
Included M3 screws:
5 in-lbs
DocterOptics mount
Front Sight
2x 6-32 mounting screws
2x mount mounting screws (6-48 flat head, torx drive screws)
Included 6-32 screws:
6.5 in-lbs
ShieldOptics mount
Front Sight
2x M3 mounting screws
2x mount mounting screws (6-48 flat head, torx drive screws)
Included M3 screws:
4.5 in-lbs
RMROptics mount
Front Sight
2x mount mounting screws (6-48 flat head, torx drive screws)
6-32 screws that came with your optic:
6.5 in-lbs
Deltapoint ProOptics mount
Front Sight
2x mount mounting screws (6-48 flat head, torx drive screws)
M4 screws that came with your optic:
6 in-lbs