My gg gc16 predator

Discussion in 'Gun Building, Modifications & Repairs' started by REAPER556, Jan 19, 2019.

  1. REAPER556

    REAPER556 Active Member

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    I just got a GC 16 predator and yesterday. And to my surprise it only chronoed 295-300 FPS with .25s using an 11.1 lipo
    The gun is amazing it’s accurate and it’s got great range. It performs like my 350 FPS SRXL, however for piece of mind, I would like to get it higher like 330 to 340 ft./s could anybody give me some advice and some simple basic mods to get me there without exceeding the 350 ft./s limit at My field. I’m thinking a heavier spring swap might do it? Idk all suggestions are extremely appreciated
     
  2. Lefse

    Lefse Well-Known Member Supporting Member

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    If it doesn't have the pneumatic blowback system the gearbox shell should withstand a stronger spring. An M100/SP90 spring with good air seal and optimal cylinder to barrel volume ratio should get close to your FPS goal and will be easy on the internals. You might have to use an M110/SP100 if you want to "hug" the FPS limit.

    G&G stock piston heads are often kinda meh, so replacing it with a better piston head with a #14 o-ring can be enough to reach your FPS goal actually. I also recommend using silicone paste to lubricate the cylinder, the stuff used for car brakes.
     
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  3. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    Is that limit with 350 fps with .20 or .25g bbs?

    A M120 will get you closer to this limit.
     
  4. REAPER556

    REAPER556 Active Member

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    I shoot .25s and I want right around 340 cause I don’t want to give or take a few FPS and shoot 355. Anywhere at 330-340 would be optimal with .25s
     
  5. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    Then M110/M115 is is what you need.
     
  6. REAPER556

    REAPER556 Active Member

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  7. link0

    link0 Well-Known Member

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    What he meant was that most fields test FPS with 0.2g BBs. If a field's limit with 0.2g is 350fps (most indoor or cqb places in the USA), that means your 350fps on 0.25g (about 380fps equivalent on 0.2g) will be shooting way too hot to be allowed on that field.
     
  8. REAPER556

    REAPER556 Active Member

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    the two fields I play at for cqb and outdoor both test aeg’s and GBB with .25 @350 FPS limit and hpa .3 @300 FPS limit
     
  9. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    Its generally 10fps per .01g. So a reading 400fps with .20g, results in a 350fps with .25g.
     
  10. mikejosephman

    mikejosephman Moderator Alligator Staff Member Moderator

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    I'd say check your air seal first before changing springs.
    Probably just losing power out of the box.
     
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  11. REAPER556

    REAPER556 Active Member

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    Like Teflon tape the hop up barrell connection? I just got the gun Thursday and it chronoed 296 with .25s at my cqb field
     
  12. REAPER556

    REAPER556 Active Member

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    Although I have heard on YouTube the predator Kronos around 290 to 300 in the stock configuration with .2 fives
     
  13. mikejosephman

    mikejosephman Moderator Alligator Staff Member Moderator

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    Yeah, if your FPS doesn't increase after that, then go into the gearbox.
    Rule out simpler problems first then go for the guts.
     
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  14. REAPER556

    REAPER556 Active Member

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    Sound advice my friend
     
  15. REAPER556

    REAPER556 Active Member

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    Ya I just contracted a new tech from New England where I live. We did a zci barrel with a gg green buck and an m nub in the stock gg hop up unit. The lonex I bought would not fit in the predator. We also bordered a lonex compression kit with bored cylinder, nozzle , and piston head etc. and a m110 spring as well. Hopefully this stuff will get me into the 320-330 FPS with .25. I was at 270 or so last time I chronoed at field with .25s. Man going from my Avalon cqc to the predator feels like a major decline lmao. Glad I can still play while I get my predator worked on. Shout out to CAM at arrowhead airsoft Wrentham ma!
     
  16. REAPER556

    REAPER556 Active Member

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    You were right . I was loosing max compression in the gg. The air nozzle was plastic with no o ring. The piston had one weak o ring and the teeth were Ground. After a proper shim and proper AEO adjust along with the lonex Pom (compression kit) bored cylinder, lonex piston with full metal teeth, m110spring . 6.04 barrel, max cyl head, gg green and some special nub “butterfly”?. But gun is a diffrent gun now. 323 with .25 and laser straight every shot. So much happier with my rifle now. Now I can use it. A lot lol
     
  17. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    Nozzle o-ring has minimal if any affect for compression.

    Leaks down and back from the pressure flow does not drain pressure as much as most inexperienced players think.

    If you think that plugging the nozzle/cylinder hole and then not being able to drop the piston is the proper compression check, one is wrong. A BB and nozzle will never ever make an obstructed seal like that. That compression test is effective for piston head seal tests.

    Also the original intent of the O-ring nozzle was made to initially compensate for sloppy tolerances on nozzle to cylinder tube "alignment". Then with Internet "Ignorance" it was turned into a fleece the newb part. It was never intended to be a compression issue part remedy.
     
    Last edited: Mar 6, 2020
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  18. REAPER556

    REAPER556 Active Member

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    Cool guges. Yet I was only listing off the parts that my predator had that were causing about 25% compression loss and how were able to remedy this stuff and solidify the gearbox with said updgraded parts. But I hear u, the nozzle has no bearing on overall compression.
     
  19. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    You can fix compression issues with teflon tape.
     
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  20. REAPER556

    REAPER556 Active Member

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    All I know is that with the new components the rifle shoots better , has better FPS than other non modified predators at my field. Teflon wouldn’t have helped as we believe this rifle was a factory lemon
    Plus when there are issues I’d rather buy better parts. I appreciate all the diy tricks of this trade, I think the quality parts however will extend the life and durability of the internals etc
     
    Last edited: Mar 6, 2020