CZ Scorpion Upgrades: MLOK and QD Sling mounts

My friend John Saunders of Saunders Machine Works helped me out with a little project I had in mind to upgrade my CZ Scorpion Evo3.

First I wanted to cut QD holes into my CZ Custom Shop buffer tube adapter. The blocky design allowed for plenty of material to support QD holes for my Magpul QD sling. The forward face of the adapter has a negative cavity, that is why you can see a gap in the rearward QD hole. I know you can see bare aluminum. I may have this re-coated, but it is not a priority for me.

IMG_5641 IMG_5648 IMG_5646 IMG_5645



The second modification I wanted to have done was to shave off the side rails and cut M-LOK slots into the sides. The side rails are a tad bit bulky and rough, especially since I like to hold the front of the Scorpion with my left hand and my thumb high.

The M-LOK slots were very easy to cut once we found the correct dimensions online. Here is a pic of the shroud cleanly shaven.



Here is a picture of the M-LOK slots that were cut into the polymer shell. The shroud already had some narrow rectangular slots above the side rails. They were wider and shorter than M-LOK slots. So we agreed to use the factory slot width and make the M-LOK slots slightly wider. We did not anticipate the bit of material you can see at the leading edge of the slots.



I purchased some M-LOK accessories and it works.



I did notice that the QD mount screws were close if not touching the barrel. So I sanded them down with a belt sander.



Here is a pic of John testing out my Scorpion for the first time. Notice where his support thumb is? That is how I hold the Scorpion. With the side shaved down it feels much better and I can still add accessories on a whim.


Nicholas C

Co-Founder of KRISSTALK forums, an owner’s support group and all things KRISS Vector related. Nick found his passion through competitive shooting while living in NY. He participates in USPSA and 3Gun. He loves all things that shoots and flashlights. Really really bright flashlights.

Any questions please email him at


  • Casey

    hmmm…must be hard to extend your arm out to use the sig-brace as designed with the sling like that…

    • Giolli Joker

      The brace is for look and weight balance, he shoots SAS style. 😛

    • First thing I thought, too. Not sure I’d be putting some of these pictures up on the interwebs.

      • Vitor Roma

        C’mon, dont be a fearful wimp. The NFA already explained that they dont care if your shoulder touch the brace, unless you do something very stupid, like a crime. In case the NFA starts to search prosecute people because their shoulders made contact with the brace, time to start a revolution.

        • Atf guy

          I’m in the van casing ur neighborhood and shooting range now….

      • Ethan

        The total number of ATF agents who even know what a SIG brace is can be counted on two hands. The number of those that care are even smaller.

        I’d say your odds are better for getting prosecuted by the Bureau of Extraterrestrial Relations for having prejudiced thoughts against Martians than being arrested by the ATF for shouldering a Sig Brace..

    • Ferd

      You don’t have to extend your arm out to shoot. The design makes it easier to shoot like that, however, you can also use the brace as a cheek rest as well which is what is looks like the author does to me. Thorenson lmakes a nice “cheek” stabilizer as another option to shooting these pistolas. Personally I much prefer the shockwave blade as you do both much easier than with the sig brace or Thorenson which were designed principally for one or the other, but can do either or.

  • ClintTorres

    Good to see he has not “redesigned” the sig brace by shouldering it. Rolls eyes.

  • thedonn007

    Very nice. This almost makes me want to get one of these Pistols.

  • Otm Shooter

    Tried to remove the barrel nut to remove hand guard (so I could do something similar)when I got mine in Feb. I tried like hell with wrench, heat, and cheater bar. I gave up.
    I see now that CZ custom sells the socket that mates with the barrel nut correctly. There is nothing to hold the gun in place, but plastic, when trying to remove the nut, BTW.

    Kudos for the success.


    • Nicholas Chen

      Yeah there is a copious amount of red loctite under that barrel nut. I used a heat gun after almost rounding off the nut. LOL

      • Otm Shooter

        Maybe I’ll have to give it a second try. Thanks!

  • Paladin

    For those who are interested, John Saunders has a YouTube channel called NYCCNC, he regularly posts tutorials and other cool videos for CNC machining.

    • Giolli Joker

      Isn’t he the same guy who recently machined taofledermaus’ slugs?

      • Paladin


  • TangledThorns

    What is the purpose of the ring on the Scorpion?