Hi, I have a Classic Army UMC (same as any other UMP on the market), which use a V3 gearbox.
I very much like using the UMP Suppressor when I play, makes the shots very quiet.. the loudest thing being the motor/gears.
The thump/pop from the air compression is perfect; it has a very nice and loud 'crack' without the suppressor, but very deep and quiet thump with the suppressor.
I would like to tune up the gearbox mechanism to be quieter; I'm guessing I'd need to change gears (I've given it quite a few shim jobs, but I'm just thinking it's the CA gears metal is loud??)
I was looking at the
Modify SMOOTH Modular Gearset 7mm V2/V3 - NANO Torque because they eliminate the need for shimming, and are advertised as quieter..
For a little insight on my gearbox parts; it's a rock stock 7mm Classic Army gearbox, uses bearings and a high torque classic army motor. Shoots approx 360 FPS. I use a 9.6V 2000mAh battery.
I do not feel the need to have higher FPS or faster ROF, or checking the compression/seals or anything else.
I bought this AEG brand new in summer 2010, I've spent approx 10,000 - 12,000 rounds so far and I do not feel it has any issues, the parts all look brand new and still solid.
The few issues I've had:
After 500 rounds I had to hammer a part of the motor because it was losing contact with the wire.
At approx 2000-3000 rounds, something on the motor cage "broke".. the motor height adjustment "screw" stopped working properly. So i had to add a spacer under the motor.. I cannot adjust it's height anymore (doesn't help with the sound issue).
I'm also looking for a Motor Cage.
So I appreciate any tips/hints or help anyone can provide me with.
Thanks