Upgrading Cylinder to Barrel Length Thread

Discussion in 'Gun Building, Modifications & Repairs' started by Infinite_Phazes, Dec 3, 2011.

  1. Infinite_Phazes

    Infinite_Phazes New Member

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    So I did some measuring along with some math and discovered my new non-ported shs cylinder to stock (9.5inche) inner barrel volume ratio is 3.2:1.

    I realize typical ratios are generally between 1.5:1 and 2:1, with the cm16 stock shorty being 1.62:1. On the 1.62:1 ratio with m130 spring and 0.20g bb's I'm shooting 390 FPS.

    When I get more money I am planning on getting a 9inch mock silencer and popping in a 469mm tight bore barrel. That will drop the cylinder to barrel volume to 1.69:1 ratio but until then I am wondering what weight BB should I use to get the best usage of energy ... 0.28, 0.30, 0.36, higher??

    Thanks for the input guys.

    If anyone is wondering how I came to this conclusion or how I did the math please feel free to comment. I didn't want to post too much info right off the bat.
     
  2. Uller

    Uller Active Member

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    Ussing .20 gram bb's as a benchmark,for every .1 gram you go over .2 you will loose 100fps.So in your gun shooting 390fps you will be shooting 290fps with .3's.Your barrel length would be fine,and there would be no need to change that portion of your set up,if you did the following:

    Exchange cylinders for a single ported cylinder,and install R-hop.I have a Dboys PDW running a Madbul 220mmX6.03mm barrel and M110 spring.With a single port cylinder,R-hop and .3's im shooting 273fps,and my max range is somewhere between 230-240ft.If I were you I would also take a look at your compression,and make sure you have no airleaks as its my opinion you should be shooting harder than you are with that spring regardless of the nonporting.
     

  3. Infinite_Phazes

    Infinite_Phazes New Member

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    Your set up sounds great. I want to extend my inner barrel to about 469mm with a 6.03 bore and put a silencer on. I havent chrono'd it with this set up yet, will update today but with the single port stock g&g blue cylinder the gun was firing at 390FPS.

    I want to get great outdoor accuracy with .25-.30 bb's.
     
  4. Uller

    Uller Active Member

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    Topeka
    Your setup as is sounds very much akin to mine with the exceptiion of the extra 20mm or so barrel length and M130 you have,and the R-hop I have.You are only shooting basically 17fps harder than I am and im ussing an M110 spring.Make sure your compression,and airseal are spot on as it sounds to me as if its not.You should be shooting in the lower to almost mid 400's with that spring/cylinder/barrel you have now.With an R-=hop properly installed and the extra power you have over mine you should easily get mid 250ft ranges.Mine shoots surpirisingly accurately,very much like a conventionally hop spacered gun.The true test will come when I finally get around to finishing the R-hop for my G3 countersniper.
     
  5. Infinite_Phazes

    Infinite_Phazes New Member

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    Just got back from the Airsoft extreme and did chrono testing with 0.20g, 0.25g, and 0.30g bb's and here are the results.

    0.20g bb's = 407 - 412 FPS
    0.25g bb's = 374 - 379 FPS
    0.30g bb's = 344 - 353 FPS

    The numbers seem pretty awesome to me and actually did better than I hoped on the 0.30g bb's. So I'm very happy. I'm just hoping that the spring settles down to 400 FPS on the 0.20g bb's so I can meet the max requirement for the field

    I will look into this R-Hop mod you speak off. I read on it briefly but didn't understand how it puts a back spin on the bb's since it looks flush with barrel, please enlighten me how it is better than tacketts hop up tune, if not I'll leave it alone.

    p.s. I also shot a video of install but want to edit it before I post it.

    In case you are wondering the internal set up here it is:

    G&G stock CM16 stock gears,
    Shimmed w/Systema Shims,
    G&G stock CM16 Gearbox,
    G&G stock CM16 tappett plate,
    G&G stock CM16 9.5 inch stock inner barrel,
    Stock Hop Up (Tackett Fine Hop Up Tuned,)
    SHS white bucking,
    SHS delayer clip,
    SHS Trigger Contact,
    Guarder SP130 spring (m120?),
    SHS Full Cylinder (Type 0) "Grooved",
    Prometheus Metal ball bearing ported Piston head,
    SHS Metal rack Nylon Piston (AOE corrected w/70d sorbo),
    SHS double o-ring cylinder head,
    SHS O-ring nozzle,
    SHS ball bearing spring guide,
    dremel polished interior gearbox,
    stock 8mm cm16 bushings,
    SHS ultra torque motor,
    turnigy nano tech 25c-50c lipo,
    16 awg wiring,
    [ame="http://youtu.be/TOkKwGWGWjs"]Disguised Enemy Mosfet[/ame],
    [ame="http://youtu.be/TOkKwGWGWjs"]Disguised Enemy 30a resettable fuse[/ame].

    What do you guys think?
     
    Last edited: Dec 3, 2011
  6. Uller

    Uller Active Member

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    Topeka
    Thats alt better,and your .3 reading is surprising given your .2 reading.Im understanding its a new spring then?If so you will probably loose between 10-15fps after settling..For best outdoor range and accuracy use .3's in it.Personally I dont buy .2's or .25's any more save .2's for chrono testing.I aceive my best accuracy with .3's in the sub 440fps range,above that I go .36's or .4's depending on my setup.There are a few threads around here on R-hop,read them and check them out.
     
  7. Infinite_Phazes

    Infinite_Phazes New Member

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    Torrance
    Thanks man for all the input.
     
  8. Uller

    Uller Active Member

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    Topeka
    No biggie,if I can be of help just ask.