one of the copper ones...solid copper.
Gives me that extra bit, knowing it can't really come apart, and awful hard to keep in an animal, so you generally get 2 holes.
If not, then any old cup and core bullet would suffice for me.
Don't really much care which of the soild copper ones, they are to close together in performance IMHO, granted I didn't run the numbers and all.. but should be awful close... I'd choose the one I like the best and had the best accuracy.
