How Does the MR920 Optic Cut Work?

Coming to you from SHOT Show 2020, where we are talking about how our new patent pending optic cut on the MR920 works. A few of you asked questions about how the optic stays in a rigid mounted position, so we’re going to explain that now.

When you take a look at what the optic cut looks like with the optic removed. You can see that we have relocated the extractor depressor plunger assembly, which allows us to drive the screws deep, deep into the slide, in fact they come out almost at the rail. Ok, so we’ve got long screws, but you’ll notice that there are no bosses or posts, so how does the optic keep from twisting? We did something a bit unconventional here. The mounting system comes with screws that are designed for each specific family of optic, for example the ones shown here are for the RMR and Holosun optics. You’ll see on the section of the screw that does not have threads that it is about the same diameter as the hole int he optic, which reduces a lot of the fit between the optic and the gun at that location. But the secret sauce is actually in the spacer. On the back of the optic cut, there are two small half circle openings in the slide that are designed to receive a corresponding half circle on the spacer. The spacer is designed with the outside diameter of the optic in mind. If you were to just mount the optic to the gun, you would have a little space at the back–we didn’t like that just from an aesthetic perspective. But more importantly even if the screws are tightly torqued and properly loctited, with a strong enough blow the optic could potentially turn or twist a little bit–and I know that because we pounded on them with a deadblow hammer as part of our testing. So what we did was to design a spacer out of extremely hard plastic. The spacer is keyed to lock into those little cavities and it is designed to be just a little bit oversized so that it has to compress under pressure as you install the optic. When you put your screw into the optic, it compresses the spacer at the back and puts it under a substantial amount of pressure. The screws are machined out of a material that is very strong in its own right and something else to note about these screws is the broach cut opening, which makes it extremely difficult to strip these screws. As soon as those screws are torqued to 10 inch pounds, the optic is drawn tight toward the back, compresses the plastic of the spacer, and creates an incredibly rigid mounting system because the optic cannot turn once it’s under compression. Each optic has different spacers to fit this slide.

6 Replies to “How Does the MR920 Optic Cut Work?”

  1. Sully says:

    Can you have the optic cut configured irons forward??

    1. JESSICA@SHADOWSYSTEMSCORP.COM says:

      We debated on this configuration, but many customers choose not to mount and optic immediately and some never do. We wanted them to have the longest sight radius possible so we chose the conventional configuration. We do not have plans to produce the gun irons forward and could not support this as a custom order.

  2. Wes says:

    I have a MR920 on order. Is there an expected ship date?
    Thanks, I can’t wait to get the 920 in hands!

    1. JESSICA@SHADOWSYSTEMSCORP.COM says:

      You should see your gun in late March or Early April

  3. Isaiah says:

    I own a mr918 and was wondering if i send in the slide will y’all do the same sight cuts on it as the mr920 has ?

    1. JESSICA@SHADOWSYSTEMSCORP.COM says:

      Hi Isaiah, I am sorry but the optic cuts cannot be added post-production.

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