The extent of my airgun knowledge is that I could do nigh-impossible things with my crosman powermaster when I was young. What's a modern recipe for a reasonably precise, scope sighted air rifle that's suitable for cats rats, squirrels and other rural vermin? Is it fair to assume that it wears a 6x FF? 22cal or 177?
.22 JSB Exact or Hades.
6X is good, so is 10X. BKL double strap rings. Parallax is critical. Set it up on a bench and mark your adjustment rings (occular or side) from 10 yards out to 60 in 5 yard increments and then use the optic to range distance to target. Note mil DOPE for future reference. Image gets clear and reticle holds hard on target when all is aligned at correct distance. Starlings will hate you....
Consider used market. Some have had a Vortex kit or other tuning done to make them even better for less than new.