Since I'm so full of good questions recently.......what do you look at to decide what powder your gonna load when your developing for a new rifle? are there specific velocities in the books vs case capacity/load density vs pressure estimates using software vs bullet weight?

obviously it can change if its just not shooting well, but ya gotta start somewhere and making a good educated guess saves lots of time and money.

Yes Im somewhat of a newbie, but not a dummy.....lol
And i tried searching similar topics, but didn't see anything to really answer my question.