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Thread: Help with m12 closed bolt semi assembly.

  1. #1
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    Help with m12 closed bolt semi assembly.

    Hey fellas!! Long time lurker here & I am in need of help assembling my m12 semi. Please post a pic if youíre able!! The very rear of the receiver (where a stock block would sit) I have no notion what the heck is going on there...
    thank you all for your time, & have a good day.

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    I have a CB semi M11/9. I imagine that the parts are similar enough to be able to give you a good idea. I’ll snap a pic when I get home this evening.

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    Thatís funny. My first post is in response to your first post. Thumbs up.

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    I’ve never figured out how to add a photo from my phone on here, but if you want to PM me your email address I’d be happy to send you any pictures you need of the internals on my SWD M12.
    Last edited by fortyfive1911a1; 05-14-2020 at 08:12 PM.

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    Side note, if you need mags, these are fantastic. I have two and they fit and run perfectly.

    https://www.ftfindustries.com/product/RP-380MG.html

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    I am interested in the pictures. There is not much info out there.
    I've been converting semi SWD M11/9 parts to fit a SWD semi M12 lower.
    Last edited by strobro32; 05-16-2020 at 01:04 PM.

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    I got stuck at work late so I'm not able to get the picture of my M11/9. I'll try to get it tomorrow.

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    The problem I'm having with Semi M12 380 parts is the hammer hits the top of the rear spacer. I had to cut a channel out of the top of the spacer for the hammer to pass through.


    In all the pictures of the M12 spacer on the net, the spacer looks like the M11/9 spacer.

    It's surprising I can not find pictures of the fire control group of a SWD M12 380 Semi on the web.

    Found one!
    In this pic, there is no 380 spacer. The semi sear plate springs can be seen behind the hammer. The upper receiver would drop down in the rear of the receiver without a spacer.

    I wonder why it is not listed on some diagrams but is sold at FTF Industries and USMachinegun.com? Is there a semi 380 spacer? I know a 9mm spacer will not fit the 380. The hammer hits it. Websites just seem to link the 380 spacer to the M11/9 semi spacer photo. If anyone has a 380 spacer, please post pictures.


    In this picture, there is no spacer in the collection of parts group either. Do 380's have or use a spacer?
    Last edited by strobro32; 05-16-2020 at 06:33 PM.

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    Still wondering if the 380s use a spacer.

    I just remembered that the MPA Mini 9 must use something similar. Here's what they use. I will trim mine to resemble theirs.
    Last edited by strobro32; 05-28-2020 at 08:29 PM.

  10. #10
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    Here's the pic of my SWD M12 380 semi fire control group.

    Last edited by strobro32; 05-16-2020 at 10:02 AM.

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    M12 Semi 380 Assembly instructions.

    1. Insert the sear plate legs under feed ramp. Slide it forward.
    2. Insert rear spacer. Slide it backward.
    3. insert the sear plate springs on each of the sear plate posts.
    4. Slide sear plate backwards so the springs seat inside the rear spacer.
    5. Drop trigger bar in front of the feed ramp. Slide trigger bar legs under sear plate notches.
    6. Drop trigger into trigger hole with the trigger bar behind it.
    7. Drop the "V" shaped end of the trigger selector retainer spring over right side of feed ramp welds channel making sure the "L" side end is toward the muzzle end.
    8. Inset trigger pin, reduced diameter side, into left receiver trigger hole while pushing down on retainer spring.
    9. Slider trigger pin through trigger.
    10. Push down on retaining pin and slide trigger pin into right receiver trigger hole. Make sure retainer pin drops into groove in trigger pin.
    11. Insert selector pin in right side of receiver hole while pulling up on "L" shaped end of the retainer spring. Make sure selector retainer spring falls into grove on the safety selector shaft.
    12. Drop hammer spring and hammer over the hammer pin holes. Push hammer spring legs between the sear plate springs, into the the rear spacer.
    13. Insert hammer pin through left side hammer pin hole of receiver, through hammer and out the other side of receiver.
    14. Attach E clip to hammer pin.

    I could not find this info. I hope others find helpful.
    Last edited by strobro32; 05-17-2020 at 04:25 PM.

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    Success! I trimmed my 9mm spacer to resemble the MPA Mini 9 spacer and it worked flawlessly. The pistol does not seem to have much trigger slap. I removed the trigger boot and it's working very well. I did ramp the bolt. I'm not sure if that contributed to the softer trigger reset.

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    My SWD M12 does not have a spacer in the back of the receiver. Just the bare receiver.

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    What keeps the upper from dropping in the rear? My hammer did not reset with the trigger pulled, until I installed the spacer.

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    Quote Originally Posted by strobro32 View Post
    What keeps the upper from dropping in the rear? My hammer did not reset with the trigger pulled, until I installed the spacer.
    My lower looks exactly like the one in the picture you posted with the red background. There is a little movement up and down if I force it in the back, but it is negligible. It’s hard to tell, but I believe the upper is resting on several contact points in the lower that keep it aligned. It looks to me like it rests on both sides of the feed ramp and also mine has that metal bar over the safety pin. It looks like your lower is missing this piece.
    Last edited by fortyfive1911a1; 05-22-2020 at 04:20 PM.

  16. #16
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    Maybe that's it. My upper drops down in the back without the spacer.

    I took both the SWD M12 and RPB M11A1 out to the range today with my 8yr old son. The M12 shot %100 reliable with the 90 rounds we shot. The sights were water bottle accurate at 10 yards. My son preferred the M11A1 w/CFW-A bolt and CT9K for mag dumps.

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