Besides Jack O'Connor and also Townsend Whelen mentioning Hosea Sarber's 172 grain load in his .30-06 on brown bears, Sarber used the .220 Wilson Arrow in 3 Model 70's using Swift barrels rechambered by L.E. Wilson on hair seals, eagles, coyotes, hawks, ravens and grey wolf with a 55 grain load. He had taken a number of black bears with the .220 Wilson Arrow, but says it is inadequate for such game even though "it kills amazingly well on certain shots".
