I grew up using the 30-06 and I still do at times.For a good all-around grain bullet out of the 30-06 is the 180 gr.This grain will take anything from antelope to bear,it also eliminates re-sighting when switching bullet weights (ie. 150's for deer and 180's for elk).
I realy don't know what pepole have against using a heavier bullet in their guns to kill game.The point of hunting is to kill it right??So it won't be any deader if you use a 165 vs a 180.What you gain is penetration,so you say whats 15 grains??It's the diffence between a pass through or stopping on the far shoulder blade.I belive animals bleed better from two holes better than one.
As for 300 yds shots the "06 can doit,sight in 2 in high at 100 and dead on at 200 and only 9 inches low at 300.A top of the back hold out to 380 will put elk in the freezer.
Granted I'm shooting 180 gr Nosler partion.
BBJ