I've taken several deer with the .22-250. There is a time when an ultra fast little bullet with do just as much if not more damage on a deer vs a larger slower caliber.
I've personally autopsied over 200 deer, so experience seeing up close and personal what different rounds do internally makes one understand why there are so many different styles/types of bullets out there now, and why they perform differently on deer sized animals.
I was particularly impressed with the deer I took tonight with a .45LC pistol round. The Hornady SST is designed for maximum expansion at pistol velocities. It made a silver dollar size hole going in, messed up the innards pretty good, and exited. Thats the way I like it. two great big blood trails to follow.
Along the same line of thought, a buddy shot a deer with a pistol tonight. 7X57 rifle round in a Magnum Research single shot. He hit her at 100 yds with a factory round designed to be used in a rifle. She ran over 1/4 mile in waist high grass, finally getting into the woods, crossing a creek and expiring.
Took us over 4 hours to follow the tiny specks of a blood trail through the grass/woods half the time after dark tonight, and finally found her. The bullet did not perform because it was designed for rifle velocities.
I guess my whole story is about making sure one selects a gun, and ammo combo that will do the job. Cheaper is not always better, and it's every hunter's responsibility to make sure they select their gear that will result in a quick humane kill on the animal they are hunting.
Hope this helped.