SIG 320 M17 RMR MOUNT W/INTEGRATED REAR SIGHT

All plates come with the LCI notch as it works perfectly with both configurations of the pistol. If you choose to not run the LCI mechanism, but have the cutout on the slide's breech, the notched plate will work just fine. Concerned about blowback (GSR) on your optic? Don't be. As we say, you're shooting a handgun and there will be GSR everywhere no matter what. The optic may require a brief wipe down after an extended shooting session. This is normal under any application of a slide mounted optic.  The striker assembly has to be removed to access the fasteners in both configurations. 

Holosun Mounting Instructions

 

IMPORTANT

 

The Holosun series of compatible optics utilize DIFFERENT screws than what is provided by Bobro Engineering for the Trijicon RMR series.

What are the differences? The Holosun screws have a smaller diameter head (top part) than what is used to mount an RMR, and the smaller diameter head Holosun screws MUST be used. Holosun provides 2 lengths, one is 5/16” (short) and the other is 3/8” (long) you MUST use the long screw.

If you use the short (5/16”) screw you will not have enough threads engaged with the Bobro Engineering plate, and this is INCORRECT.

The long (3/8”) screws will be too long and stick out past the bottom surface of the plate. You must file or grind these screws so that they are flush with the bottom of the plate with the Holosun unit installed. This maximizes the thread engagement and is CORRECT.

The plate that Bobro Engineering makes is tapped for a 6-32 screw (for the optic) and double check that the Holosun screws that you have are also 6-32 before installation. Since Bobro Engineering provided the correct screws to mount the Trijicon RMR, it is on you to ensure that the screws you use for the Holosun are correct.