Farmer Dean, 1f of any brand is too fine for shooting projectiles out of a bore your size.
For what it's worth, you probably don't need huge charges behind a projectile unless you are shooting at attacking legions from 1000 yards away. You will be able to use reduced loads with cannnon powder behind a ball to save $$.
Powder, Inc will allow you to mix grades in the same 25# box and still give you the 25# price. That being said, you can order some of each and use what is best for either blanks or ball.