Roy....
I have one of those Tasco Custom Shops 8-40x56 that sounds like it might be just what yuopu are looking for. I just took it off of that 7RUM that I was playing with. It's a 30mm scope with a duplex and when you crank it up to 40 power it's like shooting thru a rain drizzle. That ought to provide you with another excuse for them little buggars.
Evan03..
I can imagine how small those things are you are trying to hit. I can probably help you with your hit ratio without going to a higher mag scope though. You just ned one of the 50 BMG's. When one of them bullets even comes close to a rock chuck it's light out for the rock and anything within a 10' radius. Vaporized rock chuch counts as a kill. hehehe
Maybe you're needing one of them 8-32 powers.