I have been on a few Caribou hunts in the last 20 years,have shot 6 myself,every time I went I carried a 30/06 loaded with 150gr cor lockets.Worked good for me,the same rifle has went almost every fall that I didnt go and has taken over 20 caribou without a complant.My thought is that your 308 will do just fine on a caribou hunt.My one suggesten would be to make sure you have good opptics on it before you go and practice shotting alot out to about 300yds .