This was an interesting chart I compiled in the fall. I thought it was real telling that if I wanted to truck through the woods with my BOB I'd sure rather carry 22's then most anything else. With that in mind I bought a 22 pistol that complements my 22 rifle. Many suggest in a SHTF world 22's will kill anything that a larger round will, but you just have to be a better shot and aim for the head or the heart. One more thing about 22 ammo. JW Rawles has suggested that 22 rounds could be the currency of choice in a post SHTF world. Money won't be worth anything but a 22 round might get you a loaf of bread.
Ammo per pound
137 .22 cartridges weighs 51 grains. (137 rounds/lb.)
39 .223 cartridge (I think it's a 55gr bullet) weighs 178 grains. (39 rounds/lb)
35 9mm Hydrashok single 135gr weighs 199 grains (35 rounds/lb)
22 .45 FMJ weighs 318 grains (22 rounds/lb)
28 7.62x39 cartridge (122gr FMJ) weighs 253 grains. (28 rounds/lb)
19 .308 cartridges weighs 361 grains, (19 rounds/lb)
19 30-06 ammo weighs (19 rounds per/lb)
carry ten pounds of ammo = 190 rounds of 308 compared to 1,370 rounds of .22







If there are armed thugs in the area, the larger calibers give you a stand off/fend of capability which the 22 will lack, that said, I would rather have a 22 than a stick or a knife.