Can any GC2 gurus help please? I was checking my GC2 MkII today: lovely and consistent at 720fps, so I tweaked the power up a bit. Went up to 785 - great! That's where I'd set it previously. However, I noted that the adjuster screw was still turning easily after tightening up the two grubscrews on the charging plunger, and that after a few shots the power was already dropping back a bit. Should there be a second grubscrew to lock the power adjuster in place, as per a Ripley, or is there a different way of adjusting it? Does the power adjuster always turn freely like that? Any thoughts/ideas/advice? I'd like to get it up 'n running, but consistent with it. .