While I understand the differences between BPCR, Muzzleloaders, and Cannons, I feel compelled to share something I learned loading BPCR in 45-70. While the windage of a mortar or cannon barrel may produce different results something strange occured when switching from 350 grain bullets to 525 grain bullets. I was loading for fun not competition, but the chronograph had some interesting data to share. The 350 gr cast bullet loaded with 60 gr of 2F Goex the chronograph averaged 1,173 fps. With 525 gr postell bullets the velocity averaged 1,125 fps using the same charge. Since the velocity difference was so close but the energy levels so vastly different the heavier bullet flew further, and was more accurate at over 150 yards. I strongly recommend that you greatly reduce the powder charges to allow for the pressure increases as well as the increase in the carried energy of the projectile which will at least equal the travel distance of the projectile.
