Featured Can I get some techies advice?

Discussion in 'Gun Building, Modifications & Repairs' started by GSDZ19, Dec 3, 2017.

  1. GSDZ19

    GSDZ19 Member

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    So I have a G&G cm16 I bought some internals upgrades for nothing crazy mainly just compression parts. But I’m about to pull the trigger ( pun intended lol) on a cyma ak74 cmo47c version 3 gearbox. Which one is worth dumping money into for a decent dmr style rifle? I have heard some good reviews on the newer cyma aks. Full metal on the ak where as my cm16 is mostly polymer. Ak supposedly shoots high 300s out of the box.
     
  2. Hangtight

    Hangtight Well-Known Member

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    DMR Airsoft guns aren't about the base rifle. They aren't even really about the parts you buy. To make a real Airsoft DMR it's about knowledge, time, skills with tools and just how carefully you put everything together. There is a reason that it costs over $1200 to buy a genuine DMR from somewhere like Umbrella Armouries.
    But if you're looking for a solid AK with nice externals then the better quality Cymas are nice.
     
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  3. Lefse

    Lefse Well-Known Member Supporting Member

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    The AK will be a slightly better DMR platform for a couple reasons. Firstly it has a V3 gearbox which is intrinsically more durable than a V2 gearbox. Secondly, it has a more robust hop-up design and everything is locked down inside the gun, this helps with consistency. If it has a full stock there's also room for a bigger battery which helps with performance.

    It's true what Hangtight says though, a DMR isn't just about buying the right gun and parts, if you don't know how to properly install and tune everything the performance will be lacking.

    I have attempted to build DMR's on a couple occasions but I have more or less given up on the concept. First of all it's not a very practical gun to use on the small local fields, but also because hop-up mods make me angry. :D
     
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  4. LightIsRight

    LightIsRight Active Member

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    The Cyma AKs are great but don't get the 047. The 040 is the same thing but with a different construction style that is arguably better and much more realistic.

    I'm the opposite, I dislike gearbox work because its so frustrating...
     
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  5. Lefse

    Lefse Well-Known Member Supporting Member

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    We're very opposite then, even DSG builds bore me at this point, don't mean to brag though.
     
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  6. Hangtight

    Hangtight Well-Known Member

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    DMRs aren't fun to build. You take them apart a lot and twat around with a lot a shims while obsessing over how to achieve better than +/-0.5 fps.
    I'd rather be figuring out how to use a 3D printer to make bits for the box mag on my custom, scratch built HK21 LMG... Cos then I can charge around at a skirmish going full Rambo firing a machine gun from the hip.
     
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  7. GSDZ19

    GSDZ19 Member

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    You guys are awesome haha it won’t be as much a dmr as just a nice longer range rifle. Because my g&g is extremely short so that will be mostly for indoor use or small outdoor ops. I just hear the new cyma are freakin work horses!
     
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  8. GSDZ19

    GSDZ19 Member

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    Thanks for the heads up! I found the 040 so I’ll go with that over the 047. You are right same exact build. It was either that or for an extra 35 go with the CYMA advanced all metal wolverine.
     
  9. Hangtight

    Hangtight Well-Known Member

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    I should get this made up as a sign...

    Once an Airsoft barrel is over about 200MM IT DOESN'T MAKE ANY DIFFERENCE TO RANGE OR ACCURACY!
    A properly built CQB gun can be just as accurate and have the same range as a 'long' DMR if they shoot the same fps.
     
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  10. GSDZ19

    GSDZ19 Member

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    My g&g is around 320-ish but more so it’s just an excuse to get a new platform haha
     
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  11. Hangtight

    Hangtight Well-Known Member

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    See...honesty is the best policy ;)
     
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  12. LightIsRight

    LightIsRight Active Member

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    Yeah I really like the Cyma AKs. I told myself I wouldn't buy another gun until I sell all of the ones I'm currently planning on selling... but I may get a CM040 when I do buy my new one...
     
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  13. Lefse

    Lefse Well-Known Member Supporting Member

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    +/- 0.5 FPS, that's within the combined margin of error of the chrono and BB's. If you're within +/- 1 FPS you can consider it to be zero inconsistency really.
     
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  14. Hangtight

    Hangtight Well-Known Member

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    Yep, but it's a DMR and you forget that bit so you can chase yourself in circles for a while longer. That's why I like my nice, simple DSG builds... Are lots of BBs going fast in the direction I'm pointing the gun? Yes? That's a win then... :)
     
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  15. Lefse

    Lefse Well-Known Member Supporting Member

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    I do know what you mean, I also tend to get caught up in small less relevant details sometimes. I weigh my pistons with a jewelry weight that's accurate to a hundredth of a gram. :D

    OP, I apologize for sidetracking your thread, at least it's been somewhat relevant.
     
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  16. Hangtight

    Hangtight Well-Known Member

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    Is not just you, although my scales only manage 0.1g ;)

    But again, apologies to the OP for sort of getting side tracked... But this is the detail that goes into building a good DMR.

    31-32g piston weight seems to be best for 400fps and 0.36g BBs by the way...
     
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  17. GSDZ19

    GSDZ19 Member

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    I don't mind haha i'm intersted in it so doesnt bother me in the least bit.
     
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  18. GSDZ19

    GSDZ19 Member

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    Why weigh pistons? Is there benefits to lighter internals other than weight? might be a silly ?.
     
  19. Lefse

    Lefse Well-Known Member Supporting Member

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    A heavier BB accelerates slower, so does a heavier piston, if the acceleration of the piston matches the acceleration of the BB less energy is wasted. You typically use heavy BB's in a DMR and only semi-auto, so a heavy piston is beneficial, it'll also help with FPS consistency.

    In a high ROF setup you want a lighter piston to avoid PME, but if it's unnecessarily light you'll get poor compression efficiency and less consistent FPS.

    Edit: Sniped by Hangtight.
     
  20. Hangtight

    Hangtight Well-Known Member

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    Light pistons for cycle time in high ROF guns, and heavy pistons for shot efficiency and consistency in semi auto guns.
     
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