What rifle should i get (deer huntin)?

(deer huntin) I've ben useing a 44 and ben barowin a 30-30 and im gettin pissed of about sittin in a stand and a big ole buck comes out, too far for me to shoot, so im buyin a new one. right now im thinkin .308 or 30-6, which one should i choose and which one will kill the biggest the farthest??? thanx marry christmas