Featured Want to build a M4 that counts as a dmr and cqb M4

Discussion in 'Gun Building, Modifications & Repairs' started by Leandro Gabriels, Sep 6, 2021.

  1. Leandro Gabriels

    Leandro Gabriels New Member

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    Hello all

    Im someone who likes to have a M4 where i can switch uppers from so that when i play outside its a DMR and when i play indoor its a small compact package.

    Are there things you recommend to look for when doing this and / or do you have examples what i could make?

    Regards
     
  2. OPairoft

    OPairoft Active Member

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    Split gearbox like ICS, RA, or Prowin/PGC
     

  3. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    Or design it like an ARP9. M120 Spring in the AEG. With short barrel 150mm ~330fps. With long Barrel 400fps.
     
  4. OPairoft

    OPairoft Active Member

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    I completely forgot about that method, yeah that would also work pretty well. Though will need a mosfet that can switch from semi/auto to semi only.
     
  5. Leandro Gabriels

    Leandro Gabriels New Member

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    Just a normal ARP 9 with longer barrel and shorter barrrel?
     
  6. Ben3721

    Ben3721 Well-Known Member

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    So your basically trying to do what setup I have.
    This is a old photo and the guts are all different now but yeah have the aeg volumed for the long barrel, then when using a short barrel the pellet is gone before the piston even moves 1/3rd the way forward. Only issue is, there is a lot more stress when the piston has no resistance. So radius and Sorbo are very important. But if you put a amplifier on the short upper it will be incredibly loud due to the extra air. It's nice tho to just have one primary gearbox to focus on for two different field restrictions.

    [​IMG]

    Edit: quick change springs are also very common on aegs now, some you don't have to take the gearbox out at all. Just understand you can't throw a 11.1v lipo on a high speed setup on a m90 spring without horrible pme.
     
  7. Leandro Gabriels

    Leandro Gabriels New Member

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    this is what i would love to make , only a longer version of the right picture
     
  8. Jamesking

    Jamesking Member

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    Thx I was thinking of doing this for my gun now
     
  9. Jamesking

    Jamesking Member

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    But I have this is it possible with it? 17427641-4195-47CB-981D-46FA9F977AB9.jpeg
     
  10. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    That is a Classic Army Made AEG. It's possible...but your base gun isn't a high quality model so you will need extra work...
     
  11. Jamesking

    Jamesking Member

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    Ok thx for letting me know I will ask for help if I need it agin