I built up a new mechbox for testing...and the initial results are a bit puzzling...
Base:
- Guarder Reinforced mechbox (good old tried and true)
- old gear set (previously tested)
- PP hard piston
- MASK aluminum piston head (non-ported)
- MASK aluminum cylinder head
- modify airseal nozzle (m4/m16)
- bearing spring guide
- M110 spring
- M4 cylinder
- KA Hopup
- Guarder black hopup rubber
- somebrand SIG55x length inner barrel (a bit longer than M4)
- other bits & pieces
Although I've built the odd M4 mechbox before and have fiddled with a couple of AEGs in the past
...and I'm pretty sure of what results I should get, I'm open to any and all suggestions!
With a previous mechbox in this setup, I'd get just around 400fps with this setup. Compression seems fine.
Chrony after two assemblies is a very consistent 285fps w/ 0.20g. Mechbox "sounds" good (it's actually a bit noisy with the gears, but the sound of the shot sounds like a high-300fps)
I'll check the nozzle next tear down...maybe I'll swap the inner for a stock M4 barrel (hate taking off the KA hopup c-clip).
Or...I'll just swap a different piston head/cylinder head in there and see what happens.
A bit baffled with the low FPS.
Tired, going to sleep on it.
Tys