.45 ACP is the usual all-the-time carry choice but an S&W Model-60 has to suffice when physical exertion + heat & humidity create rivers of sweat and/or abbreviated shirt & shorts. [Even stainless steel can rust & the smaller 60 is easier to hide & clean. ] As for the repel boarders 12g, it's loaded with #1 shot. Our patrol cars had 00 but I prefer #1 because while being only slightly smaller than 00, it throws a lot more lead pellets at the BG. No kids here so I can scatter things about. Well hidden but quickly accessible. Only to me. OK for me but use what works best for you.
It only takes a second to dial 911; it could take the rest of your life for help to arrive. ~ Unknown