NEED HELP on hop up issues etc...

Discussion in 'Gun Building, Modifications & Repairs' started by lego7897, Aug 7, 2015.

  1. lego7897

    lego7897 Member

    538
    8
    Boise
    Hey guys, soooo... where to start? My dad recently started upgrading his VFC HK416 CQB with tons of upgrades, including but not limited to:

    SHS gears (reshimed and regreased)
    M110
    Lonex a1+
    BTC spectre v2 FET (soooo awesome)
    External stuff that I won't mention.
    Other non important things.

    All the above parts were installed well and performed great with only minor obstacles. It's when I got to installing this stuff that things got funky:

    Prommy 6.03 407mm barrel
    Prowin hop up (only one that fits the vfc 416)
    R hop and m nubs
    Multiple flat hopped buckings to try out

    Anyway, we had a reputable tech from our area install the r hop for us. When we first tested the gun we noticed quite a few quirky things: first of all, it was a bit over hopped. Secondly, it was veering a bit to the right, and finally, it was jamming for the first few shots. Another odd thing is that the issues seemed to go away as you would shoot, but completely reappear after taking a short break. So, obviously it needed to be opened up and looked at. Upon inspection I found the r hop itself to be installed very well, almost picture perfect. There were a few issues, a flab of the m nub had been torn off 99%, so I cut it off to remove the over hop (and did so successfully). Another problem was the bucking it was too tight for bbs to pass through easily and the torn m nub had been messing things up quite a bit. Unfortunately it was quite dark out when I next tested it with a different bucking, and the fixed m nub. Everything *seemed* fine until the next morning... Dun dun dun... :) Anyway, when I test fired it the next morning (today) it shot/shoots great on the first bb, then just love the rest out quite slowly as if some sort of jamming is going on. The sir nozzle cycles perfectly, going back and forwards without air leaks (I did the paper over feeding tube test). In really stumped on this one, the bucking (g&g green) is really soft and let's bbs pass through quite easily, and the r hop has been sanded at the front to prevent pinch type jams.

    Any help would be VERY appreciated,
    Thanks.
     
  2. Wingman703

    Wingman703 Moderator Staff Member Moderator

    5,547
    541
    Atlanta
    Do you still have the original parts? Swap things out till you can pin down one part that seems to cause the issue.

    What BB's, and what mags?
    Is it still overhopping? It almost seems like the Rhop patch is too big.
     

  3. lego7897

    lego7897 Member

    538
    8
    Boise

    Thanks for the help, my lord :) So, yes I do still have the original parts, and I'll definitely try that, to some degree I already have. I've used the current barrel, bucking, and hop up chamber all with success, so it must be that they don't work awfully well together. Also, I'm using some metal 190rnd dboys midcaps because this gun is very picky on mags and these are the best option we've found so far. As for bbs, I'm just using elite force 0.28s for now. They work well and get the job done for pretty good price. Oh, and the over hop has been fixed as well.

    Thanks!
     
  4. lego7897

    lego7897 Member

    538
    8
    Boise
    UPDATE: I decided to try another mag, oddly, it worked great. The bbs flew very straight and consistently. Unfortunately they only reach out to 150ft max :( I don't get it, it's r hopped really well, tuned and adjusted as best as I can, and it only gets 150ft. I mean, it shoots REALLY well during those 150ft, but I was expecting a bit more from an awesomely tuned and r hopped gun.

    Thanks in advance!
     
  5. AirsoftRyan778

    AirsoftRyan778 Active Member

    675
    54
    Baltimore
    Do you mean the bbs are dropping off, or that it becomes inaccurate, also what is your fps/fps range
     
  6. lego7897

    lego7897 Member

    538
    8
    Boise

    Read my last update, the fps is now back to normal, right at ~410fps.

    Thanks in advance!
     
  7. DreadCo526

    DreadCo526 New Member

    315
    0
    Sylvester
    what is the volume of your cylinder? with a 407mm barrel you should have just less than full volume. This is where most of your range comes from. thats the only thing i can think of
     
  8. lego7897

    lego7897 Member

    538
    8
    Boise

    It's volumed perfectly, 3/4 if I remember correctly. Thanks anyway.
     
  9. Wingman703

    Wingman703 Moderator Staff Member Moderator

    5,547
    541
    Atlanta
    Volumeing is not where your range comes from. Volumeing is an afterthought for people like me that want to do some fancy numbers to feel smart.

    Or in simple terms, Volumeing is like that pair of fuzzy dice you put on your car after spending a month working on it to get it in tip top shape.
     
  10. lego7897

    lego7897 Member

    538
    8
    Boise

    I figured as much. All voluming does is change fps and sound.
     
  11. DreadCo526

    DreadCo526 New Member

    315
    0
    Sylvester
    No that is the worst info iv'e ever seen and not all right. volume and range are directly connected. I don't know where you got the idea that volume is fancy or unnecessary but it is one of the single most important factors in any long range build. OP do what you want but i promise most of your range comes straight from volume. both of you should do a little more research on this!! and also the effect it has on fps and sound are very minimal.
     
  12. Raven1st

    Raven1st Well-Known Member

    5,521
    444
    San Ramon valley
    Can you explain?

    You talk about volumeing yet you don't explain why it is so important.
     
  13. bryanman

    bryanman Member

    632
    4
    Canada
    ...What??

    Yes, please DO explain
     
  14. Wingman703

    Wingman703 Moderator Staff Member Moderator

    5,547
    541
    Atlanta
    I too wana hear some substantial proof that volumeing=range claim. I welcome being proven wrong.

    If it does indeed have the effect you claim, whats the best ratio to set it up for, accounting for BB and piston weight, as well as barrel length and noise suppression?
     
  15. lego7897

    lego7897 Member

    538
    8
    Boise
    Even *IF* voluming affects range, the gun already has the correct volume, so it doesn't really matter. I would, however, still like to see why you believe volume directly affects range. Thanks for the help so far guys!
     
    Last edited: Aug 9, 2015
  16. DreadCo526

    DreadCo526 New Member

    315
    0
    Sylvester
    Damn with 4000 and 3000 post, i would have thought that you would have know about this some what, even if you've never tested it yourself there's other info out there. this info is most important in long barrels.

    The volume is what pushes the bb all the way down the barrel. with a lack of volume the piston will reach the cylinder head and the bb will still be inside the barrel, in effect the piston will start to pull back and suck in air against the bb throwing accuracy and range out the window. That is with full auto. In semi it will just push the bb partially down the barrel and stop pushing, meaning a lot of loss in range. I will look up some articles from hs5 as i'm sure hes argued about this before as well, and his name is respected for range.
     
  17. CrusaderAirsoft

    CrusaderAirsoft Member

    802
    17
    Winchester
    I'm pretty sure that HS5 was arguing against the vacuum effect theory for over-volumeing in threads I saw awhile back on ASM.
     
  18. Airborne101

    Airborne101 Well-Known Member

    1,918
    147
    Chicago
    The nozzle becomes disconnected from the hop up chamber on the back stroke of the piston. Therefore it does not seal with the hop up, and can not create a suction/vacuum acting on the bb. Further more, in ported piston setups, the piston is not sealed with the cylinder, so air has an ingress route from behind the piston as well. Air can also enter through the port in the cylinder if there is one in the gun.
     
  19. DreadCo526

    DreadCo526 New Member

    315
    0
    Sylvester
    No don't get me wrong, i wasn't saying if you have more volume you will have more range. I was saying if you have the right volume you will have more range. over voluming is better than under.
     
  20. AirsoftRyan778

    AirsoftRyan778 Active Member

    675
    54
    Baltimore
    I guess in theory The extra volume could create turbulence, but im not sure