I always found that the German caps were better than Reminton or CCI, meaning little or no ignition probs. CVA's tend to work better with conicals than sabots (imho) as projectiles, and (iirc) CVA recommends "power belt" bullets with their inlines. Now their inlines are faster twist than your rifle, so you might be able to also use T/C conicals or Buffalo Bullets (which may be also available) as T/C does a 1:48 twist on their plains style guns too. (IF you want something heavier than the round ball.)
I like 70 gr of 3Fg with my .530 round ball in my rifle, and it will go through a 100 lbs. deer at 90 yards with a profile shot.
ML guns all have personalities, and you need to try different projectiles and loads to find the optimum.
LD