I'd have probably put it into the advice and general help section under the AEG category, I'll move it for you and leave a link.
Kind of a sneaky way for people to still see it lol.
It depends how far you want to go with it really, you could easily sink about £1000 into it if you want to go the whole 9 yards. Gears, cylinders, cylinder heads, nozzles, pistons, piston heads, mosfets, batteries, wiring, connectors, motor, bushings, shims, spring, spring guide.
It uses a Version 2 gearbox, so there are plenty of parts available, it'd be best to check with someone who owns one first, but more or less everything intended for a V2 gearbox ought to fit fine, maybe with the exception of the cylinder and piston, depending on whether it has an extended gearbox or not, since the SR25 7.62mm stylised receiver is longer than the standard 5.56mm M16 style one.
I'm planning to sell my LSW and put the money towards an SR25, probably the G&G one. I'm going to swap out the barrel and hop first.
Swap the gears to high speed ones, that's with a ratio of lower than 1:18, get a very powerful high torque motor, an M130 or maybe even an M140 or M150 spring since my regular site have a 500fps DMR limit, shim the gearbox to perfection, lock it to semi and then run it until it breaks.
Once it caves and I have an idea of the tolerances I'll swap the parts that failed out for something better, or just build on it gradually as parts show signs of wear. I imagine to up performance further it be wise to get a bore up cylinder set, new cylinder head and air nozzle, new piston and piston head and a metal spring guide; ought to help with the consistency a bit.
Once you're past that stage, I'd maybe add a fancy mosfet to help with the trigger response. I'd be hoping that with good trigger control and correct gearing I could have the gun working well enough for it to not jam up anyway, but a mosfet ought to remove that worry altogether anyway.
Also, I'd probably just pay someone to install the parts I said, 'cos I'd rather kill myself than try and put a V2 gearbox back together with anything stronger than an M120 into it lol.
