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Gunsmithing Thumb screws for MPA BA Comp cheek/buttpad

hafejd30

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Minuteman
  • Feb 27, 2019
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    Just an fyi for anyone looking to do this. I bought a MPA comp second hand. There were no set screws for the cheek riser or butt pad. Both of which are annoying loose without them.

    Purchased some 8-32X1/2 knurled thumb screws. Just fyi the 3/8” are to short. I cut the 1/2” down just a touch

    A dab of blue loctite. Worked the screw in and out and allowed the loctite to dry. Just enough resistance when I thread it back in to snug by hand and not vibrate loose in its own

    Found the screws on eBay for $10/10 pack

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    • Like
    Reactions: Herb Stoner
    First thing you do with a mpa chassis is rip all that hardware out, including wheels. Less stuff to clean. Get the riser collars from mpa and you will always go back to the same spot.

    Those little screws are gnarly though.
     
    First thing you do with a mpa chassis is rip all that hardware out, including wheels. Less stuff to clean. Get the riser collars from mpa and you will always go back to the same spot.

    Those little screws are gnarly though.
    Hadn’t thought of replacing the parts. Just acquired the chassis for my B14R. First thing I noticed was the slop though. This is my first mpa chassis. Just like sloppy folding hinges that move when shooting but overall make the gun sound like crap when you move it around as well.

    Once I decide if I like the chassis I’ll look more into the collars and what not. Or a folding hinge for cleaning at least
     
    On my matrix pros and matrixs I have everything cranked down hard. The pop out bag rider does not move, it's locked in place. You really need to make sure all the fastners are tight.

    Phil also loves to use 95 different thread and Allen key sizes which makes taking the chassis apart a pain in the dick.
     
    Good info Hafejd30. Might have to try and get some of those. I have actually used some of the collars mentioned and they work really good but something else I have started doing, especially to the butt, is take the wheel out of its spot and put it on the outside and use it as a reference point. I wrap a little electric tape behind it so it doesn’t move from that spot and then just loosen the two set screws and it pops right out.

    And no shit on MPA using every Allen and torx head in every chassis! Lol

    I didn't do the cheek piece yet

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    Got her out today. Pretty decent. Only have 3 lots of SK on hand. Some 5 shot 50 and a 100 yd 10 shot group
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    • Like
    Reactions: Rob01
    How does that work for cleaning your barrel? Can you get the cheek rest low enough to get your bolt out and cleaning rod in?
     
    That's kinda what I was thinking. Thanks for the reply. I have the matrix as well and hate all the screws on it. And I'm a lefty so no chance of thumb screws digging into my cheek!
     
    That matrix lightweight buttstock kit is how the matrix should've been in the first place. It's well worth it, IMO. It really helped balance out my pro 2 without adding even more weights up front. I already have to run the internals and a set of gray ops XLs
     
    • Like
    Reactions: brettb614
    I have a straight taper 26" so I haven't had that issue, but it would be much nicer to leave the stoopidass Allen wrenches in the drawer. Someone should go back in the time machine and find that Allen guy and throw his ass off a cliff so we never have to use them again 😂