For use on North American game the .308 is the obvious choice as the "best" short action cartridge. It is adiquite for anything from field mice to big bears if properly placed.
On the low side (varmits) it might be a bit more gun than is comfortable, but will kill a prairie dog just as dead as a high-speed .22 caliber. There is no such thing as "too deadly" so argument against the .308 based on varmit use just don't hold water.
On the other end of the spectrum, the .308 is getting very close to not being enough gun against the largest game animals. This is particularly true against the big bears which can bite back. However, a well placed .308 shot will definitely kill any bear that ever walked.....you just have to be careful.
It has the trajectory to be effective to 400+ yards....which is as (if not farther) than the "average" hunter should be taking game anyway.
The only legitimate challenger to the .308 (in my opinion) would be the .358. It would give up just a bit of range, but also give a bit more "whump" on the largest game.
Actually I have always felt the .308 was the most versitile ONLY because of the guns it is available in that won't chamber a longer round. If one is not limited to a short action rifle the .300 Magnums would be my choice as "best" for an all-around cartridge (the .30-06 would be almost as useful but I give the edge to the .300's due to being able to send the heaviest bullets with a bit more authority).
I've never really bought into the whole short action argument anyway. The .30-06 length cartridges are available in bolt, single shot, pump and semi-auto actions and I cannot see where a half-inch shorter action is any advantage. That is however my own opinion and I know lots of folks who spend big money to build short action rifles and believe they are superior. Confidence is such a big part of success so, for them, the short action IS better.
There is one argument that makes the .308 far superior to any .300 or .30-06. The Savage 99 cannot be made to handle anything longer than the .308.....so that makes it the "best" cartridge.
