The SCM 3 should be set to a setting of about 70 PSI. You will need an AKA Valve tool for that. They are available at dc or through aka. It is very easy to set the lpr with this.
Brock hit the nail on the head with dwell as well. Also, lets not forget that you need smooth consistent paint and a matched barrel. You can't expect to shoot .685 paint out of a .691 barrel and get good efficiency.