I have used most of the above mentioned, 410, 20 gauge, 12 gauge and 22LR. My personal preference is the 22LR pistol for 2 reasons, 1.The ammo is the cheapest and 2.The pistol is easier to carry than a shotgun. My second choice would be the 12 gauge shotgun for the simple matter that it is easier to find 12 gauge shells than 410 or even 20 gauge sometimes.