SRY Tom - forgot it was a 20.

Armed with a roll crimp die, you're home set on loading your own. A 3" will hold a LOT more powder than needed & still should allow a folded crimp if that is your desire, but - 140gr.2F should net you around or over 1,800fps with a round ball weighing 320gr. in WW, depending on the diameter, for 2,303fpe.