A&K SR25 build

Discussion in 'Gun Building, Modifications & Repairs' started by sniperboi94, Sep 26, 2012.

  1. sniperboi94

    sniperboi94 New Member

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    Ok guys I recently picked up an A&K SR25 because I figured it would be a good platform to start a DMR build. When I got it from AEX(walk-in store) it was shooting about 400-415fps w/ a javelin .2g BB. I don't care about ROF because I disabled the awful full auto function this gun comes with stock. Here's a list of everything I've done with it so far and what I plan on doing to finish it. Some advise about parts would be helpful.

    Internal Parts so far:
    9.6v 1200 mah battery
    Dboys bearing spring guide
    Guarder M150 spring(non PSG-1 type)
    Bravo Aluminum ported piston head w/ bearings
    Bravo Double O-ring cylinder head
    5KU Air Seal nozzle
    King Arms 80 degree bucking
    Masamune 6.01mm TBB (509mm)

    I have an AMP high torque motor and AEG burst wizard kit that I haven't installed yet.

    Everything else is stock

    External Parts so far:
    Magpul MOE motor grip DE
    Magpul MBUS front & rear DE
    Magpul trigger guard DE
    Magpul AFG DE
    Harris style bipod
    A&K suppressor
    A&K rail panel(x2)



    image-3798230303.jpg



    image-2012882357.jpg


    Now with this set-up I'm getting 472-475fps w/ .2 it's very consistent but my target FPS is 600 w/ .2 because that will yield me about 400fps with a .43g BB. Here's what I'm looking at getting.

    Internals:
    11.1v lipo battery with a 20c dump
    Astro zero loss connectors
    16 gauge silver plated wire
    Tunable Ver. 2 trigger
    Matrix SR25 8mm reinforced gearbox
    CA super torque up SR25 gear set
    Matrix Aluminum SR25 piston or G&G nano co-alloy piston for the L85
    Systema Ver. 2 metal spring guide w/o bearing
    Systema 400% PSG-1 spring
    Reaps hop-up bucking
    Energy SR25 Stainless cylinder or CA SR25 bore-up kit if I go with a 650mm barrel

    Externals:
    Magpul PRS for an AEG DE
    Magpul RSA
    6-24x50mm mildot scope w/ micro red dot on top
    Dboys Ambidextrous mag catch

    And that's about everything. Like I said advise on parts and cheapest places to buy them would be helpful. If you guys want to through in some of your own DMR builds I'd like to hear about them.
     
  2. DeltaSupportGunner

    DeltaSupportGunner New Member

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    That pretty sick I have to say. Good job
     

  3. alex

    alex New Member

    4,794
    4
    Atlanta
    DMR builds are different for each person. Edi1st likes super fast trigger response. I prefer to reduce the load on my motor, battery and internals.

    my preference is as follows:

    element 32:1 including half teeth element partial teeth piston
    guarder poly head
    16awg or 14awg (depends on where the battery is mounted)
    home made mosfet
    7.4v or 11.1v (depends if i want a quicker trigger response)
    madbull hopup (flathop, i recently picked up some silicon tubing which i'm going to use for r-hop). use sealant on bucking.
    gearbox radiusing
    sorbo for AOE correction (i normally use rubber faucet washers for standard builds)
    stock cylinder head with teflon seal
    any neodymium torque motor works fine
    guarder sp160 gets me around 580-600 fps then settles down to 550fps (it wears down quickly to 520-530 after a year).
    stock brass barrel (shimmed with either teflon tape or foil tape).
    deepfire o-ring nozzle (shs o-ring also works great, it's a bit tighter fit).

    my range is usually 300 feet (1 out of 5 shots hits my target) using cheapo .40g

    i currently have 3 working DMR builds.

    here's a site for low priced magpul clones (free shipping) http://s.dealextreme.com/search/magpul
     
  4. sniperboi94

    sniperboi94 New Member

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    Ok so your going with the helical gears and piston then? I was thinking about doing that but it's difficult to find helical pistons(in stock) for the elongated version 2 box. But that sounds like a pretty sick DMR build though. And thanks for the link.
     
  5. alex

    alex New Member

    4,794
    4
    Atlanta
    i haven't tried the sr25 piston mod, but it's worth looking at. use a spacer between the piston head and body on normal v2 pistons to replace the original sr25 elongated piston. do a bit more research on this because i'm just repeating what i've read in the past.

    you may be able to use a cylinder buffer spacer instead. all depends on what you can find at the hardware store.
     
  6. EDI1st

    EDI1st New Member

    2,062
    3
    Fountain Valley
    Welllll, I don't want it to be like after I pull the trigger, by the time that the gun actually fires the people are gone lol
    Plus the setup that I have doesn't really stress the motor or battery.
    I can run 1800mAh 9.6 and it'll fire just fine.


    11.1~14.8 lipo
    Random spring guide
    SP170 spring
    Lonex POM piston head
    SHS SR-25 gear set with 13:1 bevel/spur
    SHS 19 teeth piston
    HS5 FET
    JG M42
    Modify 7mm solid steel bushings
    Rest of the GB is all CA

    G&P Hop Chamber
    Prometheus 509mm 6.03TBB
    Prometheus hard bucking
    ER-hop

    Range is uh....BVR ATM.....need to find a "clean" place to test it....
    Got someone from 300ft away 2 out of 2 shots.

    Uh, it's the one in the back corner...
    [​IMG]
     
  7. sniperboi94

    sniperboi94 New Member

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    Yeah, I've read about that too but I've never actually seen anyone do it. I saw that echo1 makes an elongated cylinder head so you can use the regular Ver. 2 piston and sector gear. It sounds good and all but again I've never seen it done, plus having that extra air in the cylinder helps me out quite a bit I'm using .3's and hitting a man size target 9/10 times at 250ft.
     
  8. alex

    alex New Member

    4,794
    4
    Atlanta
    sp170? that's gotta hurt...
     
  9. sniperboi94

    sniperboi94 New Member

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    Woah sounds like a nice set up.
    How are those SHS gears? I was thinking about going with the SHS Xmod high torque gears over CA because they're like half the price. I was sure about their quality though.
     
  10. EDI1st

    EDI1st New Member

    2,062
    3
    Fountain Valley
    Classic Army makes SR-25 helical gear set.
    If you want to use 16 teeth sector helical gear set, you can just use the SR-25 piston as is or remove those teeth that you don't need.
    Then add a few spacers or bearings on the spring guide.

    SP170 doesn't hurt as much as you think, it's an elongated gear box lol

    E1 SR-25 GB = stupid, cylinder head is eh, proprietary.
    You can use regular V2 GB for it, just get yourself a long nozzle.

    SHS gears, they work and take the beating.
    Just be careful with their Gen 2 bevel the teeth tend to come off.
    The newest batch looks the same as the Gen 2 but they fixed the problem.
     
  11. sniperboi94

    sniperboi94 New Member

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    Ok thanks for the heads up on the SHS and yeah I don't think anything Echo1 will be in my gearbox for a LONG time ha

    I was thinking about running what your going with just the regular Guarder SP170 but I've never heard of a build with the Systema 400% PSG-1 spring so I want to try it out. And even though the matrix gear box is 'reinforced' or so they say, I'm going to have it sent to be cryo-treated along with the gears and piston. It'll make them last about 4-6x longer than they normally would the whole process is pretty cheap too about $25+shipping for the whole process.
     
  12. sniperboi94

    sniperboi94 New Member

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    Ok thanks for the heads up on the SHS and yeah I don't think anything Echo1 will be in my gearbox for a LONG time ha

    I was thinking about running what your going with just the regular Guarder SP170 but I've never heard of a build with the Systema 400%
     
  13. EDI1st

    EDI1st New Member

    2,062
    3
    Fountain Valley
    Eh, 400% will be fun...I should get one of those springs.....or MS210.....

    Other than that...for extreme high fps...I'll just stick with gas rifles......
    800fps on 200psi without upgrades :p
     
  14. sniperboi94

    sniperboi94 New Member

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    Ahhh yea gas is always fun. I have a KJW M700 take down model pushing 600+ fps the only thing is the mags are rare and expensive.