The aspect of 200 yard guns is a little deceiving. Most of the ads claiming 200yds tend to put attention on tragectory. That light bullets in front of 150gr powder fly rather flat. A big heavy bullet in front of a more reasonable charge can be more effective, but you must really know your flight path. Take a look at some of the old buff rifles sights. they were easily adjusted or some had multiple folding leaf sights. Are you prepared to adjust for a 3ft bullet drop. It is hard to get a muzzleloader to stabilize a very long bullet over a great distance. Long bullets must be spun very fast. The fastest twist on muzzleloaders is about1/20-1/28. Look at centerfire rifles. 1/12-1/18 is pretty common. Centerfire rifles also have oversize bullets that are less likely to strip on the rifling. My arms aren't big enough nor my loading rod stiff enough to push a .458 bullet down a .45barrel.