I have fired a Burnside long enough to know it is one of the more difficult ACW carbines to get to shoot well. I will take a Smith, Maynard, or Sharps over a Burnside any day of the week! Aside from cases now costing about $4.00 apiece, and finding a proper fitting bullet, the Burnside has gain-twist rifling. I have fired enough gain-twist arms to now that gain-twist is a very unforgiving bore. It has a very narrow window of what it wants to digest and you have to find it! But, for very simple "plinking" I highly recommend using a round ball which works very well at 50 yards. Unfortunately, I have misplaced...or lost...all the dope I had for what I found to work the best in my Burnside.
J.