You may have trouble sourcing the 70 or 71-grain .228 projectiles for the .22 HP cartridge. I have a few boxes of Norma bullets (No. 65604) for my Model 99 but they are jealously guarded, and I have no idea of a source when they are gone. You should probably try to locate a source before going that way. Our importers suck!

The 5.6 x 50 R is a true magnum cartridge, similar in performance to the .22-250.

If all else were equal, the .22 HP would be a far more practical cartridge for an open-sighted drilling IMHO, because the 5.6x50R will be severely handicapped without a scope.

For the quarry you list, either one will be perfectly satisfactory I reckon!