If you are going for the best accuracy, you need to build a set of test loads with powders in .1gr increments...Keep everything else consistent...
I shoot three different 9mms and each has it's own preference in powder charges...
I've switched over to Ramshot's Silhoutte powder since it works across my 9mms, .40s, and 10mms...My Sig 9mm likes 5.1gr behind a 115gr copper jacket round nose...While it may not be the fastest round, it is super accurate...I start one full grain below max published charge and build a series and try them all, keeping a watch for excessive pressure signs, but still accepting the most accurate...
I used to have a P85 when they first came out (1987) and never could find a round that was accurate in it..I understand the later models are much more accurate..I think it's just a matter of finding the right combination for them..