I'd say it depends on what you call a rifle rd.
There are 10mm loads that match the 223 softpoint in effectiveness, and the 223 has an awesome stopping record. Nobody is stuck with the silly fmj load. The military "ball" bullet (in all calibers) is uniformly acknowledged as being inhumane for taking deer, because it usually lets them run for 100 yds or more after being chest hit by such a load.
If you want 2000 ft lbs of impact energy, then the 308 is not a "real rifle rd" beyond 200 yds. In fact, with some loads, in an 18" barrel, it's not up to delivering such performance at 100 yds.