Go for the really expensive ammo. 22 Hornet.
If I were you, I would go for something in .223. You might be able to find an used Savage 24F-20. It is a crack in half over under single shot rifle shotgun combo. I have a 22lr 410 combo made way back when (59 I think) and it is a great gun. Plus, the shotgun can be used for the close ones.
