short of a turkey, a bird aint WORTH a 12 ga shell, if it's shtf, and turkeys are so big and slow that it IS feasible to hit them in flight with a .22lr rifle. :-) I've taken a lot more birds "on the sit" with a .22lr rife or pistol than I ever hit on the wing with a shotgun. 1000's more, actually. The shotgun's advantages are illusory, actually.

12 ga slugs and muzzleloader balls drop like rocks and drift in the wind like balloons. In the field, you wont get spotter shots and there are no wind flags. Under field conditions, the single bead of a shotgun wont let you reliably hit a deer beyond about 75 yds with slugs. A KY rifle might let you double that range, but the lack of rapidfire is a silly handicap to put upon yourself.

A typical riot barrel, using 00 buck, wont reliably get more than 3 pellets into the 10" circle of the chest beyond 25 yds, and some wont do so beyond 20 yds. The pattern often has head-sized holes in it at 20 yds, so a man using cover can be missed even tho your patten is centered on his head when he exposes himself to fire at you. Each of those pellets, at 25 yds, has no more power than a .38 lrn (non plus p) from a snubby has at 10 ft. So 2-3 such hits are no guarantee whatsoever that the guy will be stopped.