I think you mean Blackpowder in general rather than Flintlock in particular. I can't imagine hunting with Flintlock unless you enjoy cold damp morning with lots of sparks and little BOOM.
As for Blackpowder hunting, you can go with a modern BP rifle with a scope that shoots Sabots, and is loaded with Pyrodex instead of actual black powder. New Thompson Center, CVA, or Traditions rifles are popular.
Or you can go old school with a historic reproduction like the Thompson Center, Lyman, or Traditions Hawken rifles or any flavor of cap ignited Kentucky or Pennsylvania rifles.
There are tons of options.