I refuse to even acknowledge any argument that starts off: "Well, I don't think hunting rifles should be banned...." I could care less if you can or cannot hunt with a particular rifle. An AC556 set on tri-burst would make a fine hunting rifle (legalities aside).
No one should have to justify whether a particular gun or rifle can be used for hunting. In fact, hunting and "sporting purpose" have nothing to do with the 2nd Amendment. This is garbage that the antis made up. The bottom line is I try never to fall into the "anti-trap", where they make statements premised with unsupported factual conclusions and then expect you to respond. That's exactly what they do when they mention "hunting" or "sporting purpose".