It's always a difficult choice to make, for me. For all bunnies in all conditions and cover it's either a 20 bore, flintlock Virginia Fowler, not too dissimilar from Evil Twin's, or a 12 bore Pedersoli double loaded down to 1 oz. of #6's. A 20 bore, flint double would be nice but I've not come across one.....yet.
ET is correct. A fleeing bunny with a flinter can be a humbling experience....several times in one hunt!!!!