I am considering buying a shotty for self-defense and possibly shooting clays, never shot one before and know little about rifles/shotguns. My research here and elsewhere suggests Mossberg 500 is the way to go. I would prolly go with shorter barrel since Self-D is primary issue. My questions relate to caliber. How bad is the recoil on a 12 ga.? Should I consider a 20-guage? Also where does .410 ga. fall in the mix?