KWA SR-12 problems

[Muff-in]

Ok, so I recently purchased a KWA SR-12 with a 2GX gearbox. There are a few problems with it and I have looked all over the internet for answers. I want to turn it into a DMR shooting around 450-500 FPS. It needs a new piston, piston head, and cylinder/cylinder head, but I am not sure what to get for it as KWA has compatibility issues. So what piston/piston head and cylinder/cylinder head should I get for it? I also noticed that the nozzle seems to be proprietary so would I need to get a new one as well? I really like the stock KWA parts, as they have near perfect compression, but I can't seem to find any stock cylinders for it anywhere.

Also, the hop up seems to be semi-functional. So I figured I probably need a new bucking/nub. What would be the best kind for a DMR set up? And is it worth getting a R-Hop or even a ER-Hop?

So if anyone has built a DMR from an SR-12, please point me in the right direction or give me some pointers. I'm looking to spend anywhere from $200-$300 dollars on this gun to make it a nice DMR.

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Keep the stock cylinder and cylinder head. They are some of those special parts. SHS makes great pistons, and I've been really enjoying Guarder's piston heads recently. That and a new spring and you should be all set. There is a good possibility you'll need a new motor, as I've had stock motors burn out on M150s, so you might want to take a look at that as well.

As for the bucking, the 2gx bucking is great and all, but it really struggles hopping anything heavier than .28s, and even those are pushing it. Currently, the ER-hop is the best thing on the market for DMRs, short of a custom build hop up. The r-hop works well too, but isn't as strong as the er-hop for hopping .36+ bbs. The nub would be fine for an R-hop, but an ER-hop is quite a bit more involved instillation wise.

[Muff-in]

Ok, I have a Matrix-3000 High Torque motor; would that be sufficient? Also, where could I buy a new stock cylinder? I did not see it one KWA-USA.com

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What's wrong with your current cylinder?

And yes, I believe that motor should work. I have no personal experience with it though. Can you put it on your fridge and it won't fall off? If you can, then yeah, it's a good motor.

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Yes, I can. The KWA motor barely has any magnet power... It barely holds a screw.

Well I don't know if there is anything wrong with the cylinder, but I'm not sure if it's the stock one or not. Aren't barrels that are longer than like 400mm required to have a full cylinder? Cause my cylinder has a hole in it.

Also, someone told me at a game that you do ER-hops. What exactly is require to do one of those? If it's to much work, I may look into getting you to do it for me.

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If you're running a 509mm barrel, generally, full cylinder is necessary. However, that is assuming that there are leaks in a system. A Type 1 cylinder can be used if the compression is good enough. It just depends on the system. Try getting a Guarder Steel cylinder. You will have to dremel it down for it to fit, but it's steel, thus all one material, so you don't have to worry about it as much as you do other kinds of cylinders.

ER-hops require modification of the barrel window and the hop up unit as well as the hop up bucking itself. It also requires custom fitting of a rubber patch, gluing the patch to the bucking, and installing a new nub into the system. The window on the barrel needs to be lengthened, meaning it has to be cut to size for the ER-hop patch. The Hop Up Chamber then needs to be cut to match that hole so that it can properly apply hop.

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Ok. Sounds like I will contact you later about installing an ER-hop .

One more question, what kind of piston and piston head do you recommend? I know you said SHS and Guarder, but should I get a polycarb piston and a flat aluminum piston head or should I get the ported piston head?

Thanks for all the help by the way.

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I'd suggest an SHS 3 metal tooth piston and the Guarder Poly carb piston head. You don't want aluminum piston heads, for the most part, they are heavy, and cause too much force on the gearbox, causing it to crack. KWA gearboxes aren't immune to cracking, they crack just like any other "normal" v2 out there. KWA really didn't fix anything by adding all the reinforcement up at the front.

And it's my pleasure. I enjoy helping people.