A rifle,hands down would be my choice..Unless state law prohibits it..Especially a bolt Action rifle,theres no need for semi automatic,because if you miss the first shot,unless you're good at the "Run and Gun"..then your target is as good as gone anyway.
Rifles are so much more accurate to me than a shotgun,granted,theres no replacement for a good ol' American 12 gauge pump. But they aren't my prefered method of harvesting meat.
Personally,I use the Mosin Nagant M44 for my hunting needs,good range,reliability,awesome acuracy. Weight is somewhat an issue,but if you have a rest that eliminates that. Plus the stopping power,for what you need it to do. Is overall decent.
Unless of course,you live in Indiana,and such guns are illegal to hunt with,then you pull out your Winchester 12 Gauge and your good to go. But if you have a choice,then a rifle would be the first thing I'd pack.