I will certainly work this up per normal practice... mostly just wondering if working towards the same final charge was reasonable.

Looking at 5.7g Power Pistol per the Alliant 2003 data for the Hornady 147 XTP, min COAL 1.140 (I used 1.150).

Alliant online quotes 5.0g at a shorter COAL for a Speer GDHP, without saying if it is a max or not. Lymans 3rd says 5.0g for a Speer TMJ at a much shorter 1.115 COAL.

And again, I worked up to 5.7g with an XTP, and this Zero bullet seems to be on the safer side of that, given the same charge and COAL.