My -06 bolt gun like heavy bullets and shines with 200gr Sierras. The way you find out what your gun likes the best is try different weight bullets and try different powder loads until you have something that is consistently accurate.
With a new high quality rifle, the barrels these days are consistently awesome, but if you have an older rifle, I would recommend slugging the bore first to see what size your barrel actually is. For some rifles, they will perform significantly better with 0.311" bullets. I have a Spanish Mauser, for example, that is 2' at 50 yards with 0.308" bullets because the barrel slugs at 0.315". I feed it 30 caliber pistol bullets and it shoots great.