It depends on the shooter, my good Uncle Sam taught me to shoot 1000 yds, can I kill the deer at 1000yds, yes, will I find that deer before the vultures, maybe. I don't need any deer that bad to chance it, but at 500 yds with my 300 I can make the shot with no more concern than any other person with a 30.30 at 100yds. I practice at 500yds and more, 1000 rounds a year with multiple guns at those ranges, 2 inch groups with my 300Win Mag at 500yds I can easly drop the deer. But this is the one problem, unless you have a spotting scope on the deer you can't judge the deer, because bino's don't have the power to tell how many points the deer has and considering most deer, bear, elk are shot in lower than optimum light you may not be able to tell if another animal is behind the one your shooting. I don't recomend shooting over 300yds for most people with any round, my rule is the 308 Win has an effective distance of 600yds and the 300 Win Mag has an effective distance of 1000yds, derate those numbers and say the max distance for the 308 is 300yds and 300 Win Mag is 500yds. Below is my MAX recomendation for deer, but remember production guns need a good gunsmith to tune them before I would try this.

30.30----------150yds
308------------300yds
30.06----------400yds
300 All---------500yds (except 300 Savage)
25.06----------300yds
7.08------------300yds
280-------------400yds
7MM Mag-------500yds (All including STW)
270-------------400yds