I would give a slight edge to 7 RM for target (400 yards) accuracy. This is for my small comparison of only one ,270 Wby. mark V rifle using both 130 and 150. It would hold tight groups on 100 yard targets but the five shot 400 yard groups were larger than both my 7 RM and regular .270 Win.
However, I have given some thought to re barreling a rifle to .270 Wby and specify 1-9 twist with a view toward using 150 gr loads.
No experience with .264 WM
