I have used 5.3 grains of HP-38, which is the same powder, just with a Hodgdon label instead of a Winchester label. Hodgdon shows that as a maximum charge at 834 fps, but I chronographed at only 700 fps which doesn't even make the power floor for IDPA. Maybe my powder is going bad or something???
Not sure what's up with the data. My Speer manual says 5.6 max, my Lee manual says 5.1.
