Shooting the 1701P -- full stock -- I get a strange noise when I cock the pistol, kind of a high pitched squeal like I'm getting a tiny pulse of air squeezed out of the valve? Anyone experience the same strange sound? It doesn't appear to cause any issues, nor does it appear to cause any great reduction in the cylinder pressure. Seems to happen at all pressures in the cylinder, from 2400 to 1500 psi.
Cocking your pistol has no effect on the valve.
I suspect your hammer is dragging and need some lubrication..
Lube the cocking handle as well.