While I don't approve of shooting big game with minimum cartridges, I'm not going to change anyone's mind; God knows I've tried. But rather than being looked upon as the beginners cartridge due to its light report and gentle recoil, as is often touted, the .22 center-fires should be considered the expert's cartridge when big game is the target. If everything goes well, the game dies quickly, sometimes very quickly, but other times due to poor bullet choice, poor marksmanship, or just due to bad luck, things don't go so well. The expert tends to make his own luck, while the novice must take what comes. Having said that, across the arctic, thousands of caribou,, wolves, seals, and dare I say polar bears, are killed with .223s and .22-250s. Many a northern native would wonder what all the fuss was about. But I submit that there is a difference between a subsistence hunter after groceries and an annual deer hunt conducted for sport.
FWIW, and no one cares what I think, the .243 with premium bullets should be considered the starting point for small to medium big game, and if the rifle is to be a general purpose big game rifle, one of the 6.5s is a better choice for the hunter concerned with recoil and blast.