Airsoft outer barrel not centered

Discussion in 'Gun Building, Modifications & Repairs' started by Big Chungus, Sep 16, 2021.

  1. Big Chungus

    Big Chungus Member

    39
    2
    New York
    I recently installed a 10 inch troy trx rail from an echo1 onto my cyma receiver with the corresponding outer barrel. Everything fits not issue, and after everything is installed I notice that the outer barrel sags down to the right a bit, it is noticeable especially with a suppressor attached. There is no barrel wobble, everything was a secure and snug fit. Any tricks to fix this? I was thinking about adding a shim such as a rubber o ring washer at the end of the outer barrel but that would not allow it to sit properly inside the upper receiver, and probably have the same issue once its tightened down anyway. Possibly try another brand outer barrel? thanks
     
  2. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

    8,423
    4,738
    Minneapolis
    Nothing is made to a standard. You may have to "bend" that outer a bit...
     

  3. Ben3721

    Ben3721 Well-Known Member

    745
    383
    Id advise against bending a outer barrel unless it's truly bent. More than likely the upper receiver front face infront of the threads needs sanded until the outer barrel sits straight. However most rails are not straight at all and can trick your eye into thinking the outer isn't straight. A long arrow or bar snug in the outer can help you check if it's straight to the lower receiver back screw hole.

    For a real ar15 there is a receiver lapping tool to fix this issue but it won't work with airsoft.

    Most don't pay attention enough to notice this issue.

    Edit: so I looked up the rail your using, I've installed them before, on rails that have bottom screws to clamp down it tends to pintch mostly on the very back letting the rail sit off to one side a bit and down a bit due to the metal bending when tightened. Or at least that's how it seems when I've used them.

    If its off more than 4mm then I'd consider it a problem. Especially if you want to use iron sights.

    If its just off a hair, don't ocd about it because a replacement rail may be off just as much.

    It's still worth checking if the outer barrel is straight to the receiver just to rule it out.
     
    Last edited: Sep 17, 2021
  4. Big Chungus

    Big Chungus Member

    39
    2
    New York
    thank you for the reply. From what I can tell, the outer barrel is straight to the receiver. The rail now looks straight once that was installed as well and it seemed that the outer was pointing a bit southeast if you are looking at the tip of the outer barrel. I will add a photo here. I assume I would have to sand more of the top area on the face of the upper receiver threaded area just before the threads so it would tilt back up? I seemed perfect until I tightened down the 2 screws on the bottom as you mentioned. If you dont think it is that bad which I dont think it is, maybe i should leave it as it. I also though of possibly adding a small washer in between the tightening screws on the bottom, maybe that will help it not favor one side as much.
     
    Last edited: Sep 17, 2021
  5. Ben3721

    Ben3721 Well-Known Member

    745
    383
    It's really hard to eye ball it to see what's wrong.

    If its the outer barrel then yeah sanding the receiver really can make a difference if it's just off a bit. Then check with a long long barrel or a arrow to see if its straight to the upper receiver back end.

    I've done this correction to 4 m4's so far. And I corrected buffer tubes that have the same issue.
     
  6. OutlawAirsoft

    OutlawAirsoft Active Member

    288
    97
    Hamilton
    I can definitely see it. Does it affect where your shots are going compared to where your rail is pointed? Is it off enough to notice?
     
  7. Big Chungus

    Big Chungus Member

    39
    2
    New York
    The original outer barrel is a 15 inches and the keymod rail that came on it stock is 13 inches. It sits straight but I would have to assume that is due to the gas block assisting with that. This troy rail doesnt have a gas block. Im wondering if it is possible to get one on there. I havent tested shooting yet since I am waiting on parts for the build. That is the true test and I can deal with it being a little off and adjusting left or right slightly when I shoot to adjust for that but would like to avoid that if possible. I need to possibly get some sort of gas block in there but it didnt come with one originally on the echo1 platform. I know the kits on evike come with them since it is a bit different of a trx troy rail than this.
     
  8. Ben3721

    Ben3721 Well-Known Member

    745
    383
    Some cheap aegs us a extra wide gas block that bends to outer barrel to the rail, that isn't ideal as it should free float like a real ar15.