in the hands of a skilled marksman, there are alot of good long rage shooting calibers that can take down deer or bear. the 30/06 was used by many accomplished marksmen in 1000 meter shooting matches. lately that has been replaced by the .308. i havea cousin who has killed deer at 600+ yards with a 7mm Mag and can still group well at 800-1000 yards(documented on video,although i havent seen the video) My personal reccommendation is the 30/06. I have hunted with it since i was 11 and the farthest i ever had a deer run was the first buck i shot(i got buck fever and pulled to the left and hit it in the liver) and it ran about 2 steps before it hit the ground. that was with 150 grain loads. it is possible to get loads up to 220 grains(wich would be plentyfor black bear) and clear down to 55 grains(i am told, once again i havent seen these) which would be good for varmints...well bad for the varmints but good for the shooter
but i dont pretend to be an expert, someone will probably tell me that my cousin could not shoot like that, blah blah blah, but in WV we tend to pick up a rifle at a young age and put it down only when we are no longer able to hold them (sometimes after that) and i doubt that anyone who has seen west virginians shoot would bet against us in a shooting match