I've used the 50g CCi Gold Dots, and the 50g Federal HPs on coons, possums, and groundhogs a good bit. I never draw my conclusions from one or two attempts. I've shot a dozen or so groundhogs with each load, and about as many coons, and possums between the two loads.
The best hands down so far have been the CCI TNTs. They're accurate, and hit harder, with more stopping power than any other 22 magnum ammo I've ever tried any a revolver. They exit my 5.5" Single-Six at around 1560 fps, which is fast compared to most other 22 magnum ammo exept the CCI Maxi-mag +Vs.
The TNTs have been very accurate in several Single-Sixes for me.