How to Mount your Optic (Optic Ready Slides ONLY)

Optic ready pistols come with the cover plate pre-installed and torqued at the factory.  We use medium strength blue Locktite on the screws, but they can be removed with hand pressure and a typical hand tool.

Screws require a torx T-10 driver and should be torqued to approximately 10 inch pounds.  If you do not have a torque wrench and are using a typical hand tool, most people describe this as “very snug, but not excessively tight.”

Medium strength blue Locktite is recommended for mounting screws but is optional.  If you choose not to use Locktite, we recommend re-torquing screws periodically and after every range session.  Loose screws can cause zero shift.  If many rounds are fired with the optic loose, thread damage could result.

Your pistol will come with a total of 5 screws.  THE SCREWS ARE DIFFERENT SIZES.  Please note the following:

  1. Cover Plate Mounting: Use 2x 1/4 inch long screws.
  2. Trijicon RMR Mounting:
    1. 1x 5/16 inch long screw goes on the EJECTION PORT SIDE
    2. 1x 3/8 inch long screw goes on the NON-EJECTION PORT SIDE (we add the 3/8 inch screw to maximize the strength of the mount as there is space for it when mounting the RMR. However, a 5/16 screw will also provide adequate strength).
  3. Holosun 507c Mounting
    1. Use 2x 5/16 inch screws.

Call us if you need replacement screws.

16 Replies to “How to Mount your Optic (Optic Ready Slides ONLY)”

  1. Alex Beckworth says:

    I’m trying to mount a plate for a vortex venom on my Kimber KHX Custom, and the stock screws that hold the stock sight plate are too tall to fit under the venom sight. Will your countersunk 1/4” screws thread into my Kimber slide?


      Hi Alex, I wish we could help but we don’t know the thread specifications for the Kimber.

  2. Marlin Begalke says:

    Will vortex or holosun optic fit right in the 918, the dimensions seem the same but I’m unsure and want to know more before buying the optic.


      The MR918 can fit an RMR or SRO from Trijicon and a 507c or 508t from Holosun. Unfortunately, the Vortex does not fit the MR918. However, the MR920 will accommodate the Vortex and other brands.

      1. Julien boudreault says:

        Hi i have a vortex sight. Do you have a solution to fit on the mr918 ?


        Hello, unfortunately the Vortex sights do not fit on the optic cut on the MR918. The new optic c ut on the MR920 was created to solve for this and does fit the Vortex Viper.

  3. Trung says:

    Will I require a sealing plate with my RMR?


      Yes, you’ll likely want to use one. Without the sealing plate water, oil and debris can get under there.

  4. Patrick H Morgan says:

    Was wondering if I needed sealing plate for attaching
    a holosun507c to my mr920 elite. If so what would you recommend?


      Hi, you do not need a sealing plate for Holosun, as their case is fully enclosed. We do recommend one for the Trijicon RMR, as its case is not fully sealed.

  5. John says:

    Good evening, I have a shadow slide and mounting a 507c to a factory RMR cut. The 5/16 4-40 recess mount screws don’t hold the sight in place. It rattles in the cut.

    1. Jessica Roe says:

      Hello John!
      It sounds like the slide you currently have had the old optic cut on it. It’s an earlier vintage than the Holosun 507. Don’t worry though!  The easiest way we have found to get things secured is to use a type 2 RMR sealing plate.

      This sealing plate acts as a shim right raise the housing up. Unfortunately the dimensions of the housings of the RMR and 507c are not identical.

      If you need any further assistance or clarification, please feel free to call or text our Technical Manager Richie at 469-343-6831. He will be ready to take your call.

  6. Jonathan says:

    I’m trying to mount a Vortex Venom on my MR980 Elite and finding that when the screws are lined up the back of the optic will not seat in the cut, about a 1/32inch overhang. Do you have any solutions or should I get a different optic?

    1. Jessica Roe says:

      Hi Jonathan, Unfortunately,the Venom is too long to fit the optic cut. The Vortex Viper does fit and has been tested to work great with the MR920.

  7. Jakob byars says:

    I have the ss9c and I need the 5/16 screws like 10 and I’ve tried calling like it says to but I can’t get ahold of anyone I can even pay for them but they strip quick and I need to get my 508t on

    1. Jessica Roe says:

      Hi Jakob, Our offices were closed for the July 4th holiday weekend, which is why you didn’t get an answer to your phone call. Here is the link to purchase additional screws for the old-style optic mount:

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