Shotgun for me, if all we're talking about is practicality. Have taken deer at 200 and my biggest black bear with a shotgun, and my wife has taken deer and moose. I fail to see how a "modern muzzleloader" would do better, and there's be more hassle in at least two ways.
While I fully appreciate why the modern muzzleloader exists, if I'm going to hunt with a muzzleloader it will have a side-lock with a hammer, a wooden stock and open sights, and be filled with black powder and round or Minie ball. I have two of those, plus a couple of scoped and accurate rifled-barrel shotguns. Why would I hunt with a modern muzzleloader?
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
