JG Dmr build thread

Discussion in 'Gun Building, Modifications & Repairs' started by Navy100, Jan 3, 2013.

  1. Navy100

    Navy100 New Member

    Looking to build a dmr with my jg m4 s-system, my budget is about 100+$. This is just to start out until I have more money to pour into this gun. Thank you if you can help me!
  2. jon_wallace95

    jon_wallace95 Well-Known Member

    Wow, I was about to post this exact thing then I searched, I also have an s system and am wanting a dmr, I talked to some friends who have made ak dmrs, they said first get a TBB, and replace hop up bucking. Then do all the air impression fixes and upgrades: ie piston, piston head, o rings, all of that (they recommended a ported piston head off ASGI, I'll try to find the link for you). After you have fully re done the piston and compression move back to the spring and motor, bigger spring = more fps, and stronger motor to pull it. Now that you have a better motor and spring, you need some better gears to pull the spring and bolt back, upgrade those, shim it all correctly, and based off what I have been told by friends who build guns, and stuff I picked up from some highly experienced members here, you should have a pretty decent dmr, I'm sure one of those aforementioned experienced members will come and correct any mistakes I have made, possibly post links to correct parts, and help the both of us, as of now I have the hop up done, and the TBB, with the TBB be careful on full auto, it tends to not really jam, but it temporarily looses accuracy as a stream goes through, but on semi it is perfect. Hope this helped some!

  3. theonlyBuster

    theonlyBuster Active Member Lifetime Supporter

    S. Florida
    What your goal velocity and range?
    Will you be doing the upgrades or taking the gun to someone else to do?
  4. sonsofthepatriots1

    sonsofthepatriots1 Active Member

    For hop up don't forget to use an rhop. Bucking for a DMR I would use a hard prommy or lonex. For piston make sure you adjust AOE which need a hard sorbo. A soft one can be used for quieter applications but they die faster. A prommy 6.03 should be enough. I might have forgotten things but those are the basics.
  5. CoppertopNeasg

    CoppertopNeasg New Member

    Oh my god, oh my god, Marine, Marine somebody searched!!!
  6. Navy100

    Navy100 New Member

    I don't do we'll with internals so most likely someone else. Range probably 200 ish feet if I could get it there. Velocity, enough to feel it with a rig on
  7. Robin-Hood

    Robin-Hood Active Member

    I would suggest a different external set. The SIR System Bi-Level is a very out dated rail kit, it was ditched by SF in under a year because of how ungainly and heavy it is. If I were you I would highly recommend a different set up for a DMR, the SIR System is really not suitable for a DMR, you'd be far better off with a 14.5" AR with almost any modern free float rail kit.

    As for your build, it's going to be hard to do much for $100. My suggestion would be a Madbull or Prometheus Ash Barrel, R-Hop, re do the internal build and get it running smoothly with a semi-auto modded selector plate. Add a simple mosfet and power it off an 11.1v LiPo. Depending on your local limits you could up the power level to 450-500 or something. Make sure you use at least .30g BBs, though really you should be using .36 or .40s at that point.

    Either way you should get past 200 feet if you do it right, my Mk18 shooting 360 +/-1 gets like 260 feet max range with .28s

    Good luck.
  8. Navy100

    Navy100 New Member

    Do you know where I could find some of these things on one website so it will be easier?
  9. TeamDropKick

    TeamDropKick New Member


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