Building the ultimate M21 Semi-auto Sniper platform

[Katana]

What's up guys, long time no see. Coming back from Afghanistan, and looking forward to playing with everyone again. I am interested in building a beast of a sniper rifle to play with, so I came here for some advice on how exactly to build it. I am looking to spend about a grand or less on it, so I want the best parts. Wanting to build an M21 replica with scope and silencer on it, and I want shoot around 550-600fps.

In the end, I want it looking similar to this:




I am going to start off with this rifle that I found on Ohio Airsoft's boards:



Stock Rifle: Tokyo Marui M14 SOCOM
Externals: G&P Body
Bipods:
Silencer: G&P mock silencer
Scope: Leapers illuminating cross-hair red/green 3-9X50 scope with TM scope mount
Cylinder: Modify Cylinder Head
Gears: -Riot SC Gearset (Either the GS-T, or GS-T2.)
Piston: -Supercore
Gearbox: -Modify Bushings
Gearbox: -Modify Nozzle (if the stock one doesn't have an O-ring)
Motor: Systema Magnum
Battery: 11.1v Lipo
Gears: -Eagle Force Pinion Gear
Cylinder: -Modify Cylinder
Piston: -Modify Piston Head
Electrical: -AWS Mosfet (At least the Sentry)
Spring: -Modify SP140 or 150
Electrical: -Deans Connectors
Barrel: PDI .01
Hop up: Systema Bucking
Mags: x2 King arms mid-caps

[Fridge Gnome]

at 550-600 fps you won't be able to use it at most fields I think.
I would suggest

EdGi 6.03 barrel
KWA 2GX hop up bucking
SCS or PCS nub
M160
Systema magnum motor

I am not sure what kind of internals CA has stock, but you may need new gears, and other parts too.

BTW welcome back.

[Katana]

Yes, it will be over the limit on some fields, so I will probably just buy a spring that keeps me at 500fps as well as a spring that gives me 550-600.

[Fridge Gnome]

ok, but you may not see much of improvement in 550(which is secret cities field limit I think) and 600.

[vulrath]

Holy stuff, Katana's alive. I didn't think we'd ever see you around these parts again. Welcome back.

In my experience, CA M14's are kind of hit-or-miss. I have a friend (who doesn't play all that much any more, but that's another story for another time) who got the M14 Scout model, and it has been nothing but trouble since Day One. First, the negative lead on the motor side came broken; no big deal, I soldered it back together. When it happened four more times, we started looking at the gun a little closer. Turns out that there was too much ribbing (internal reinforcement for the stock itself and support for the upper assembly, gearbox and all) in the inside of the stock. The motor leads were rubbing against that, and I needed to replace the insulation on that wire a couple of times. We eventually fixed the problem with a piece of sandpaper taped to a length of pipe, and carefully and slowly removing material from the area in question.

We got that problem taken care of, and moved on to upgrading the rest of the internals. I replaced the internal mini-Tamiya plug coming off the gearbox with Deans adapters (that, thankfully, went off without a hitch), and removed the fuse. I opened the gearbox and added an M130 spring. Should give me around 450FPS with 0.20g's, right? Wrong. The gearbox (unbeknownst to me, since I thought everything was fine when I had the gun apart) wasn't sealing properly, and the gun was chronoing at between 150-250. I tear it apart, and no matter what I do, I can't get compression (at the time, we couldn't afford aftermarket piston head or anything like that; the hardware stores around here don't even sell the kind of o-rings that I needed; besides, I was still used to work like on my TM, where all I did to the gearbox was replace the spring with an M110 and add a metal spring guide, so I didn't think I needed to replace anything). I reassembled everything, and suddenly it worked, so we took it to the next game, where the spring guide broke. I fixed that, and the compression problems came back.

We did replace the inner barrel, but nothing "interesting" happened there.

Now the gun won't fire without a shim we fashioned out of aluminum foil and placed in the internal trigger assembly.

While I don't have any experience with them, I believe you'll have better luck with using the TM as a base.

And I do believe that 500-550 will be more than enough. I've seen my own springer do some crazy things with that much.

[leco510]

[vulrath]

Leco, I believe the CA is actually a hybrid of v3 and v7 parts. All I know for sure is that I won't be using one as a base for another sniper rifle for a while.

Another thing that I noticed but forgot about is that the CA seems to have a different-pitch thread on the end of the barrel where the flash hider/silencer goes. Tried it with two silencers, and neither one worked (to be clear that it wasn't the silencers, one had both cw and ccw threads).

[chrisdetrin]

id go with TM as the base gun for the record i like its metal assembly better then the CA and just put on a G&P body.

[Night Roamer]

I had good luck when the new Echo1 M14's...completely Marui compatible and upgrade flawlessly. Got his to 500 at 17 a second on a 9.6.

[SOAP]

I played in three operations using only my echo1 m14.I cant tell you how good it is and ill sell it to you cheap lol

[xandman]

[chrisdetrin]

[xandman]

Not to mention that the Marui and G&P share mags and Marui style mags are cheep for mids and highs. The CA mags are more or more expensive and midcaps are hard com come by in large numbers with out spending over 20+ a mag.

[Ares51]

To pull that big spring i would suggest a g&p m160 motor, and some bravo high-tourque gears, and a bravo poly-carb or supercore piston. And once have that big of a spring you should probably use an 11.1v lipo. Also due to the high velocities, i recomend getting a reinforced mech-box. You should also definitely limit it too semi-auto so it can be classified as a sniper rifle at most fields...

[vulrath]

He plans on making it semi. It's not a sniper rifle if it's full-auto. I'd say that a 7.4v lipo should be enough to pull the spring, as well. Though the voltage does help some, the amperage is going to matter more. On that note, a capacitor bank wouldn't hurt things either, if you're willing to play around a little and test the waters there, so to speak (theoretical gains in trigger response are pretty good, but we all know that practice is different from theory).

If you don't go with high-torque gears, then I suggest Systemas for standards. I've seen one of those go through the teeth on an aluminum piston without a scratch afterward.