User blog comment:Kogath/Monster Hunter 4 Ultimate for the Nintendo 3DS/@comment-25083735-20150325235056/@comment-5853890-20150327002909

You will take more damage as gunner because you have less defence in trade for range/kiting and better element resistance. Ideally you are not suppose to take hits and kite, not be a sitting duck like most gunners I've seen online (even in G Rank).

As for the peirce arrow thing, it's critical distance starts from near point blank I believe.

Monster HP in double+ hunts are nerfed compared to normal solo monsters, you just might not notice for whatever various reason.