As Youper and Sam have said, 748 and 4064 have been go-to powders for the 30/30 for years. I might add 3031 is a good one for this cartridge. I used to reload a good quite a few rounds for my old Marlin 336 when I was a kid. I haven't loaded much for the 30/30 in many years but if I were to start experimenting for it again I would grab a jug of LeverRevolution. The Hornady manual makes it look tempting.
