I would say the rifle you are most comfortable with. I am pretty sure people will give me a hard time for this. But for me. I would take either my .17 HMR, or .223. The .223 will get the out there 3-400 yards. I would use .17 up to 200, and focus on head shots. just for fun. I love my .223 though, and the .17 is just plain ol' fun. w/ 20 grain game tips and all head shots, they will drop. However .22-250, .220 swift, .222, .223, .243. 270. all would do well. Shoot some people will use a .308 even it's not like your going out for bear. That's why I say find your favorite rifle, and the load you are most accurate with, and just have some fun.