RE anyless than 4 buck will be defeated by a heavy coat.
I call this utterly false.
Maybe at 50 0r 60 yards, you can defeat BB or 2 or 4 shot with a heavy coat, but I doubt it. I still carry maybe 20 #6 shot in my neck and back from a hunting accident fifteen years ago where I got sprayed when a bird got up and then came back between the line of hunters, and the novice just followed the bird and fired. I was maybe 35 yards away but they (the pellets) went right through my hunting vest, jacket and heavy shirt I was wearing. Only the fact that I saw what was happening and tried to turn and duck prevented me from getting my eyes shot out.
IN a house, the furthest reasonable shot is going to be ten yards and most like far less. At five yards, a load of 8's will blow a big hole right thru a 2x6. I have seen feral dogs shot at 5-7 yards inside a barn that left fist sized holes all the way thru the chest when shot with 6's or 7 1/2's.
Walk around your house and figure what is the longest possible shot can make, then get a couple of chunks of road kill or the like and shoot that with a shotgun at the distance your house will allow. A big rec room will probably average 14X20 your stairs are maybe 17 feet top to bottom. kitty corner from kitchen to Dinning room maybe 25 feet. Loading up with a rifle for that distance makes no sense. An ounce and a quarter of BB or 4 buck or even 00 is going to hit as a single mass at the distances we are talking about. No one wearing a vest, hit with a shotgun blast at in the house ranges is going to be immediately returning fire. You will have time to say, hmmm one more for good measure, if you hit body armor with a shottie at 5 yards.
Before you go tossing statement around that a heavy coat will stop a load of BB, KNOW what you are talking about.