Seafire, a buddy and I used to shoot a ground squirrel field every Spring that we called "The Two-Brick Field." It was about 100 yards by 300, and we walked it the long way. We'd shoot 10 ground squirrels, take a few steps, reload and shoot 10 more. Repeat until we'd walked the length of the field, or burned through one brick of .22LR. Then turn around and repeat, going back. 2,000 shots, hardly any misses. And when we got back to the truck, the field would look like it was moving there were still so many squirrels. I don't know how or if the owner ever got any crop out of that field, but I doubt he did.
