Shotguns

Bradford Angier opined that shotguns were a poor choice for wilderness survival because they use heavy ammunition to hunt small game. I will touch further on this and also mention a few things about home defense. The United States Air Force, as early as World War Two issued .22Long Rifle/.410 shotgun over/under shotguns for crashed aircrewmen to forage small game. Military survival expert David Canterbury extolls the virtues of the single shot 12-gauge for carry after the world ends and lonely survivors are scavenging the hills.
Relatively inexpensive for the working person to own. Easy to clean and unlikely to break. Versatile ammunition choices for game from birds to bison. Brenneke slugs have been used to slay elephant, if that is a hazard. I must mention that the USA hosts more tigers than India, and they sometimes escape or are let loose. Relative light weight and the ability to fold into a pack are plusses in my book. David goes on to show how a single shot can be loaded with black powder (or substitute), some rags and BB shot or fisherman's split shot. He has videos on you-tube.
I currently have a single-shot break open shotgun on order (for over a year now). It comes with replaceable, screw-in, chokes to adapt to various game. I don't anticipate going after less than turkey or goose and have hosted a black bear on my kitchen porch. The gun will be fitted with the Metrogun barrel that quiets the report to that of dropping a phone book or shutting a car door. If I must hunt for meat, this will be less likely to attract envious attention. The Japanese holdouts on Guam hunted during rainstorms, but it can go for months without rain in California. To be clear, I live in the mountains and may have a good supply of shells in the cabin.
Jeff Cooper touted the virtues of the short barrel hammer double shotgun for home defense. The hammers can rest down for decades with no spring pressure to cause metal fatigue. This virtue is shared by double action revolvers which is vital for gun owners whose first shot is to save their own lives. The wasp nests should be cleaned out of the barrels fairly regularly. The double shotguns with double triggers can loose the use of one action and still have an operating firearm. These guns are called lupara or wolf guns in Italy and loaded with #3 or #4 buckshot (called loopers).
000 triple aught buckshot is .36-inch diameter and weighs 70-grains each. This is roughly what was fired by the Colt Navy Civil War six-shooters. They have proven lethal to a hundred yards, so I use the smaller #4.
We see where police officers, involved in shootings, are fired even before they can report the incident. Home defenders are prosecuted for brandishing firearms while rioters are freed without bail. These situations mirror those we have seen in Chile, Argentina and Venezuela. Sometimes, it has proven prudent to use Less-Than-Lethal ammunition to fend off looters without getting slapped with a murder charge. All our physical, social and legal situations are different and subject to rapid change. I will be getting some rubber ball or bean bag shells in case the bear comes back. One can sometimes ricochet lead shot off pavement into the ankles and shins of rioters, but I haven't heard of this being used since the 1960's. Ricochets off paving tend to deform and follow the ground rather than bounce like a basketball. 
The Los Angeles Police Department issued pump action shotguns before the Watts riots. They faced snipers and found that pumps could not be operated as easily from the less exposed prone position as easily as autoloaders. Shots should not be made into a mob of mostly peaceful demonstrators, but only at exigent threats such as individuals with firearms or fire bombs.