This is a fun what if question.
Out of my safe it would be my Ruger M77 Hawkeye African 9,3x62mm big game. It kind of fits nicely between a .35 Whelen and .375 H&H for power with recoil about like the Whelen.
Next would be BRNO No. 5 Deluxe .22 LR for most small game. It is accurate a reliable.
The last gun was a harder choice. A shotgun makes sense if waterfowl, and grouse are to be taken sportingly as they should be, on the fly. Then again, really being a sportsman is all fine and dandy if survival isn't on the line. You can shoot sitting ducks, limb swat a lot grouse and kill still rabbits with a .22 rifle.
So, I'm down to a hand gun as my third choice. Even now when hunting and hiking I carry a handgun. Here I mostly carry a 2 1/2" 19-3 .357 mag. We're talking bear, big bear and moose country. While hunting rabbits and grouse with my BRNO No. 5 .22 I would feel much safer with my 5 inch pre 29 .44 Magnum...you just never know what might be around the bend.
Me and the 9,3
because it shoots like this
the BRNO
5 inch pre 29