Lar,
Unless you used a filler to compress the load that is why you got the amount of fouling you did. BP needs compression to burn in the cleanest most efficient manner. You would also find that your accuracy would improve also provided your bullet was the right size. In the N-SSA we typically shoot about 15 grains of 3f with a filler in our 44cal cap and ball revolvers and can go through a whole match of team shooting with out the gun binding up. I shoot a cb with a 45 colt conversion cylinder with a 250 grain .452 dia bullet on top of 30 grains 3f and I can shoot it all day long with out it binding up and no loss of accuracy. BP is unlike smokeless in many areas.
Mack
hitler, stalin and mao were progressives in their time