There are a few problems I'm trying to address.
#1) If the gopher makes a "dive" into the hole before I get the clear shot... So I'm thinking I need like 40-50" of dirt penetration as a minimum requirement.
#2) The Humane kill.. I find hunters have a responsibility to abide by the theory of a humane kill. Why let an animal suffer??
#3) The Snipers Code: One Shot, One Kill. The first shot is not guaranteed as it is, and the second shot has even less chance in the odds department. You want to make sure that you have enough firepower to effectively drop the varmint with one shot. Why waste a bullet due to inferior ballistics?
#4) Wind. Since the target surface area is so small, a little bit of wind might ruin the shot. "Bucking Wind" will become a primary concern, even for small distances.
#5) Gopherzilla. The increasing use of biotechnology on things like corn and soybeans means that we really have no idea WHAT SIZE these varmints might grow to.. This is of course, a disturbing throught. So here, it seem prudent to select a caliber that can "grow" to meet the needs of the rodents of tomorrow.