Matthias - one thing to be aware of is - unless Huma have updated - the gauge they supply can't cope with 5000psi. Doesn't stop you filling it to the full pressure but the gauge goes off the scale - so I rely on my compressor gauge to know when to stop!
I have a GK1 V3 in .22 and added the Huma regulator. Yes - you can still adjust the power with the screw in the handle. I have the regulator set at just over 100bar as it was delivered. I haven't tried to wind the power up very much. I was more interested in shot count. I'm shooting just over...
