To delineate my experience I have shot BP in cap and ball revolvers and sidelock rifles since I was 12. I'm now 30. I've owned half a dozen Knights and 2 TC inlines. I have shot a few smokeless muzzleloaders and own two. I do 99% of my own gun work and handload for all my guns including slug guns. I shoot for a living.
I think there is a significant difference in performance. I have shot a Bad Bull using a 275gr bullet at 3148fps to 510yds. I have shot the Savage ML-II (stock rifle except for pillar bedding) with that Barnes Original to 302yds. Bullets for this discipline are getting better and better and the performance gap is growing.
I would never try that with my Renegade LRH and PP bullet.
Could I? Maybe with enough work but I spend half of my time training or deployed so I rarely put in for draws out west (I just buy preference points). I know I can come home, grab an SML, open a can of Hodgdon/IMR or Vihtavuori and get busy confirming zero and hunting during muzzleloader season.
The OP mentioned BP but I think he just mis-spoke. I am pretty sure he meant muzzleloader. His thread was hijacked over a technicality. Both courses of action he mentioned were for smokeless. While BP may clean up easily it does require more immediate maintenance. I would never shoot a BP/Sub gun and not clean it, put a load in it, and hunt with it all season.
I know for a fact you can do that with an SML. I also know for a fact my muzzleloaders are more consistent than my slug gun which was also one of his original concerns.
