Graham, even after using a broken in hyper 2 reg on my DM5, and ST Reg on my DMC, I never was able to get this type of consistancy.
You can put this down to user error on my part but the Pi reg came straight out of the box and was able to perform like this.
I was using a HP Throttle air system.
I have ammended my post above, as I confused Operating pressure for Cycle pressure.
I trained last night and with the LPR set at 3/4 Turn out(approx 33psi CP), Dwell at stock 18, it ripped without any problems. We train at an Indoor site and believe me when I say it is not heated, on most occasion it is warmer outside the building than in the arena!