Project: m4 II

Discussion in 'Gun Building, Modifications & Repairs' started by pancakemix56, Jul 18, 2012.

  1. pancakemix56

    pancakemix56 New Member

    So my friends younger brother has a jg m4 that is very used but I'm buying it for $50, and what I plan to do is to do as much as I can without spending money.

    So that means a lot of tuning.
    I feel like I need to go back to the basics of tuning before taking on big upgrade projects.

    So first off, the previous owner didn't do much to take care of the gun so I will clean the barrel.

    Next, I am planning on cleaning out the motor using distilled water (credit to "epicupgradetime" YouTube channel)

    Then it's time for deans, I have tons of spare deans lying around.

    Next, I will open up the gearbox, clean and polish it.

    I will then shim it, regrease and adjust aoe.

    I might try to Swiss cheese the stock piston, if it breaks I have a couple of other stock pistons lying around.

    I am going to try my best to get the best compression possible (stretching/replacing the o-ring.)

    Finally, the only upgrade part I plan to put in it is a systema bucking. I have one lying around from the first project m4.

    Later on when I feel like spending money, I plan on upgrading the outer body to metal and maybe the internals.

    Tell me what you think or if you have any suggestions.


  2. Courage

    Courage New Member

    Oh boy, is it this time of year again? This will be fun...

    Are you dead set on Swiss cheesing, that's usually for RoF builds, if the piston is already well used, plus it being made of china plastic could cause some issues down the road. But, if you want to, go for it, just make sure that you don't compromise the integrity.

  3. pancakemix56

    pancakemix56 New Member

    Lol, I don't care if I break another gun, it's the only way I will learn. I'm not set on Swiss cheesing but it is something I would eventually like to try.
  4. Njnewland

    Njnewland New Member Lifetime Supporter

    Swiss cheesing is fine for this.
    It just lightens the piston. It's not like he is going to be getting PE on this build, but this won't hurt anything. If anything, it will increase the ROF ever-so-slightly. Nothing noticeable though.
  5. Batman

    Batman New Member

    You can also help your compression by Teflon taping around the cylinder head and front of the bucking. You could also radius the cylinder window.
    Last edited: Jul 18, 2012
  6. M4Ever

    M4Ever New Member

    San Antonio
    I have seen some swiss cheese jobs drastically increase ROF, maybe that was just a specific gun or piston, but it was quite noticeable.
    It's free (practically) so you can't complain. Do it!