At variable distances out to 50 yards, it is very nearly a guarantee that only a good dome will provide sufficient accuracy for small game and pests. By that I mean reliably hit a 3/4in (19mm) diameter zone to produce a clean kill, not just a hit. On occasion you may find an exception…Hades, Polymag, Baracuda Hunter Extreme are some examples worth a try. Just don’t be too disappointed if they spread out to 1 or 1.5in (25 to 38mm) groups or worse at 50 yards. Rather, consider yourself lucky if they group tightly.
For distances of 30 yards or less, I usually go with a .177 wadcutter for squirrel- or pigeon-sized critters and smaller, but generally at no less than a 750fps muzzle velocity (roughly 10fpe for a 8.2gr pellet). That’s because, as BlackIce stated, you have to be mindful of adequate penetration and at some point a wadcutter’s blunt face just doesn’t penetrate sufficiently. Granted, the 750fps minimum figure I gave is a self-imposed limit to give a high confidence level under real-world conditions. Less will suffice under more ideal conditions but that’s a judgment call each person has to make for themselves.
For larger critters (e.g. raccoons), it’s .22 or larger. Brain shots only with domes to ensure penetration through bone, especially a frontal shot where there is a risk of deflection striking the shallow angle of the forehead.
I hope this helps!