As to the .22 killing big game, Nosler brought out the 60 grain partition bullet.
Barnes TSX and TTSX bullets work very well on our mule and white tailed deer.
Local friend of mine uses his .22-250 on mulies. He has shot 4 deer with it and all deer were in the middle of fields. His load using
IMR 4064 IIRC and driving the 45gr. TSX at 3,800fps only. It is an accuracy load, not a top vel. load.
3 deer dropped dead on the spot, shot through broadside and exited.
The 4th, walked 4 steps in a tight circle. Shot through the front of the chest, exiting behind the last rib on the off side.
When he used the Ruger #1 in 7x57 on them, with 140gr. Hornady SP at 2,900fps, every deer shot in the same field, made the bush, then dropped.
Same broadside shots, but no exits. Go figure.