I have been working on a plan for TEOTWAWKI as a part of my continuing prepping hobby. Of course, there are many things that we need to consider: Communications, food, water, transportation, etc. Bug out kits.
In the area of defense, we have selected the 9mm cartridge as the defense round of choice. Although there are handguns in the house that are capable of firing all of the popular pistol ammunition: 9mm, .357Sig, .40S&W, .45ACP, we felt that the 9mm was best for a number of reasons: it is light to carry spare ammo, recoil is manageable, and it is available in firearms that everyone in the family will carry. The round is also widely available. This doesn’t mean that I will be selling the other guns, but this is the round that I will plan our BOBs around, with each BOB containing a 20 round box of 115 grain +P.
I have selected the M&P40 as my personal handgun, and have fitted it with a 9mm conversion barrel from KKM. That gives me the capability of .40S&W, .357Sig, and 9mm in one handgun, with only a quick barrel change.
Also, for room and area lighting, we have elected to go with the UVPaqLite. It needs no batteries, doesn’t break, and provides excellent light for dark-adjusted eyes. Take a look, it is a good product for a reasonable price. It is easier to cart this around than a pile of batteries.