Hmr usefull for the extra range and still relatively cheap, about the same as a shotgun cart. CF you have a choice of loads, .204, .22 hornet, .222, .223, .17 etc.
For me it would depend on how much longer stuff you will actually do, and if in the future you will kill any fox as well.
It would also depend on how much damage you want to the bunny and hare meat!