Do you mean a "pure" Ranger? So only having a Bow and never a melee weapon?
I can't believe I can survive every battle only using a bow (pure ranger) and Ranger Skills ..; especially in dungeons with a few melee fighters or a Chieftain !! I think I'm stone dead in a fast way !
I play most of the time with a bow in open area's, but mostly everywhere I fight I use also Mage Skills, Warrior Skills and Priest Skills and a melee weapon too if necessary .
But I think it IS possible to play a pure Ranger on lower difficulties than nightmare, yes.
(but to be honest : I'm rather a slow player

, slow with 'hand-eye-coordination' )