Why not go even larger in the shot and make it ONE .22 cal pellet instead? It’ll be more suited to a squirrel than ANY size shot you can fire through that thing.

When you increase the shot size, you cut the pellet count….and shotguns rely on you having enough lead in the spread to hit and kill with. Cut the pellet count and you lose that ability.

an “air” shotgun that shoots a #9 shot shell. never herd of it