RE: chucks...
Ha, a 30-06 is just a little over kill on gophers. I'd like to be the first to call shanagans on your 300 yrd shot. For starters you'd be hard pressed to see one thats 300 yrds away. Secondly you don't strike me as one to be capable of staying steady for a 300 yrd shot, not to mention you would need a pretty high power scope to make the gopher look like a gopher and not just a tiny blob. What scope did you use?
I use a .17HMR on gophers and they'll blow all the guts out of the gophers if using the balistic tips (CCI's .17 ammo licks the left). The farthest i've managed to shoot with the .17 is 140yrds with a 2.5-10x40mm tasco varminter scope. i've decapatated many gophers with the .17HMR. Its cheap to shoot so you can go all day crackn off rounds.