I cast my own .58 round ball and sometimes minnies. My zouave really doesnt like minnies though and the reason I went to a .58 was for round ball knock down power. I bet that .54 of yours points like a magic wand.
A nicely balanced .54 is a real thing of beauty. I have been working up round ball loads out of my bp 12 gauge. It is suprisingly accurate out to about 35 or 40 yards. I havent worked up the nerve to order a .690 mold yet though.