RE: Benelli R1
Both are fine cartridges but personally I would (and did recently)go withthe 308 unless you are going to routinely shoot bullets of 200 grains (the 308 doesn't seat those as well as the 06).In summary, the308isalmost the ballisticequal of the 30-06, is shorter, kicks less,and is generally considered to have a veryslight edge in accuracy.
I have owned and shot both so youcann't go wrongwith either one.