my view of the .30-06 has always been, 150grs on most stuff, 180grs on the big or dangerous stuff. However if you can't find a load in 150grs that shoots well perhaps a 165gr would be more ideal.
I think 150grs with the 06 is perfect though, its like the 130gr with the .270 IMO.
don't be suprised about animals not dropping/dying on the spot, hunting ain't TV!
as long as you can make a good shot don't worry about an animal running off, a good shot = dead animal.
so many guys I hear worrying about tracking an animal, no blood etc..., don't even let that enter your mind, make a good shot, be confident, and if you put the bullet where you're aiming, you'll be very successful.