There are several other water purification techniques, including iodine, various types of filters, or even ridiculously expensive desalination systems. The recent Flint water crisis highlights the value of permanently installed and well-maintained RO units. But for short-term survival, my take is that most of the filtration systems targeted at preppers increase costs without offering clear-cut benefits. And really, don't overthink it: if the choice is between dehydration and drinking straight from a scummy pond, drink from the pond.

Perhaps interestingly, there is a handful of rifles chambered for handgun ammunition. Canonical examples include Ruger 77 series, Henry Big Boy, and some of the modern-day clones of Winchester Models 1873 and 1892 (e.g., Chiappa 1892 Alaskan). In the prepper context, their appeal is that you only need to keep one kind of ammo for two types of firearms. Putting a handgun caliber in a rifle gives you greatly improved accuracy, virtually no recoil, comparatively quiet operation, and somewhat improved range - but going past 100 yards is still going to be a stretch.
In some parts of the world, extreme heat can be far more dangerous than cold. When AC is not an option, it's usually possible to avoid trouble by staying in the shade, drinking a lot, and limiting physical activity. If it gets really nasty, the best way to cool yourself is to wet your clothing and hair, then stand in front of a running fan. You have a bigger problem if you happen to be stranded in a broken down car somewhere in the middle of a desert - but carrying some water and several other supplies in your trunk should help a great deal. More about that soon.
Since then, the direction has been inauspicious. In January, 2016, after increasing military tensions between Russia and NATO, and the Earth’s warmest year on record, the Bulletin set the clock at three minutes to midnight, the same level it held at the height of the Cold War. In November, after Trump’s election, the panel convened once more to conduct its annual confidential discussion. If it chooses to move the clock forward by one minute, that will signal a level of alarm not witnessed since 1953, after America’s first test of the hydrogen bomb. (The result will be released January 26th.)
Most shotguns pack a substantial amount of recoil and can easily bruise your shoulder - although lower-powered loads or smaller-gauge variants (e.g., 20 ga) can be operated by small-framed or younger shooters. Capacity typically ranges from 2 to 8 shells. A very affordable, popular, and reliable type of a shotgun is pump-action (reloaded by racking the slide); two of the best-known examples are Remington 870 and Mossberg 590.

This is by no means an exhaustive or comprehensive list of the items available for your long term food storage program. You can tailor your program to your tastes and your budget. Remember the key elements are calories (LOTS), nutritional value (Vitamins and Minerals), storage life, storage space, and flavor. By consulting this list however, you can get a pretty good idea of how to get going on your program.

With that goal in mind, let me say this:  this is not a list of items intended for deep storage. Nor is it a list of items packaged so that they have a 25 year shelf life.  (And in reality, do you really need your stored food to last that long?)  I am also not going to list items that might be foreign to your palate, difficult to find, or too costly to absorb into your weekly shopping budget.

One measure of survivalism’s spread is that some people are starting to speak out against it. Max Levchin, a founder of PayPal and of Affirm, a lending startup, told me, “It’s one of the few things about Silicon Valley that I actively dislike—the sense that we are superior giants who move the needle and, even if it’s our own failure, must be spared.”
The Ultimate Survival Kit is the perfect upgrade for your survival needs.  Built to be durable under the most extreme conditions this bag will hold the contents of any of our survival kits as well as extra clothing and other personal items that you will need in an emergency situation.  There are 6 external pockets for easy access to your supplies.  The laptop compartment makes this a great daily commuter bag.  External straps allow you to strap on extra supplies and gear.