If you or your readers are contemplating carrying a rucksack [or backpack] of any type for any distance there are three items this old soldier heartily recommends:
1. Compression type Smart Wool Socks
2. Two Toms brand Sport Shield Liquid Roll On.
3. Insoles: Green Super Feet
I am still ruck'in these days (an old LC-1 pack frame with 40lbs of weight plates zip tied to it [I am certain I am quite a sight if anyone is up at 04:30 AM]), so I believe I know what I am talking about. Six to ten miles per day. I wish I had figured this all out while I was on active duty!
I have noted specific manufacturers, because, these are what have stood the test of time and miles for me, your mileage may vary. If you find a less expensive substitute that works, please share with the rest of the class.
I have not had a single blister since discovering Two Toms, not a one, not even a hot spot.
I have old school OD Green Jungle boots and new school, feather weight USGI boots, pick your poison, neither cause me problems.
BOOTS: Boots come in all shapes construction. Costs run from reasonable to WTF? From a ruck'in perspective, you need to find a reasonable compromise of: (1.) shock absorbing functionality; (2.) mid sole flex; (3.) ankle support; (4.) insulation.
SHOCK ABSORBING: Most newer boots seem to incorporate some form of running shoe technology in their construction. If you are purchasing via mail order, do some research.
FIT: Fit is important. I purchase boots 1/2 size larger and 1 size wider than normal running shoes. I normally wear a 10.5 running shoe, so I purchase and use an 11 wide boot. Your feet will get hot and expand while ruck'in. Plan accordingly.
FLEX: When carrying a load, your boot needs to flex in the middle or you find yourself "...stomping..." and "...clomping...." with weird top of foot pain. Hold the boot by the heel and toe and push your hands together. The boot should flex in the middle. Don't get pig-headed about it. Forget the brand name, or what your buddies swear by. They are probably miserable because they did not put in the thought that you are putting into your ruck'in system. Buck the trend and do not become a casualty.
ANKLE SUPPORT: A good ruck'in boot should be at least eight inches tall to support the ankle. If your foot comes down on a rock and your ankle begins to twist, a well made boot will protect your ankle. Good laces help with ankle support. Do not tie ruck'in boots too tight, when your ankles swell and your feet get hot, you will wish you had tied them looser.
INSULATION: This is a relative and very personal item. A few years ago, during a blizzard, I purchased a pair of insulated Danner Acadia's, they worked great, but I have not work then since, they are too danged hot! When you are ruck'in, your feet will get hot. On cold, wet and/or snowy days here, with my 40 lb ruck, my un-insulated boots serve me best. If I was in an ambush or snipe hide, I'd probably lust after those insulated Danners, but down over boots seem to do the trick for me these days.
BELLVILLE: These days, my go to boot is the Bellville Model #590. They are well made (this pair is going on 500 miles plus with little to no wear), good shock absorbing, good flex, excellent ankle support, fairly light in weight and good insulation (it snows here and is wet, a lot). Sierra sole (watch for mud accumulation), speed lacing (excellent), mid calf cut outs (enables boot flex). Running shoe technology. After walking on concrete at the gun show for six hours, you will not be sore. After 10 ~ 12 hours in the woods hunting, you will not be crippled.
ALTAMA: Altama's are a great value. They used to make an OD Green, Sierra Sole jungle boot which is still the holy grail of good ruck'in footwear. If you can find a pair that fits you, enjoy them. Their like may never some again. Altama's come with either the SIERRA or PANAMA sole configuration. The Panama sole is a good one, it seldom collects enough mud to become a skate board. They come with eyelets or speed lacing system, speed lacing systems are a great leap forward.
DANNER: When I was on active duty, I could not afford them, now I can and I do love them. They run the gamut from feather weight to concrete overshoe weight, but it is hard to argue with their quality of warranty. If you are purchasing Danner boots, test drive them with the insoles you will be ruck'in with. Danners can be cozy, you may need to experiment with width and length with your preferred insole. Do not assume that your normal size will work with your preferred insole and a Danner boot. Word to the wise.
Good insoles are essential. Most default insoles, under the load and stress of miles and weight will dissolve rather quickly. My best experience is with the SUPERFEET brand.
They are stout. I have at least 500 miles on this pair with a 40 lb ruck and they are still going strong. They are coated with a blister reducing green material that has yet to separate from the insole underneath. They do not seem to pick up foot odor either.
This brand is made to work with several different foot arch contours, so do your homework and get the color, arch that fits you best.
As a soldier, I was sold on USGI OD Green, double thick wool socks, until I did some homework and discovered, SmartWool, compression socks.
The best I have been able to come up with are the Smart Wool PHD Ultra Light. I have purchased these for myself and my spouse, even she likes them.
They are long lasting, fit close to the skin, never ever sag and bunch. They are not cheap, but if you only have your Leather Personnel Carriers (LPCs) to get you around, they do not seem that expensive.
TWO TOMS SPORT SHIELD LIQUID ROLL ON:
Who says you can not teach an old dog new tricks? This stuff is just plain amazing. I roll it on the heel, top of foot and where my toes meet the flat of my foot. Put on socks. Settle into the ruck and get moving. No hot spots, and no blisters, ever.
I am not kidding, this stuff works so good I keep extra in the truck, by the bed, in the bathroom, etc...
You will hate spending the money the first time, and kick yourself for not spending the money sooner after you have experienced it.
So, what is the bottom line? I can not tell which is the single item that makes the biggest difference: Socks, Two Toms, Insoles or Boots, but thinking of them as a unified, ruck'in system, this system will work in your favor, support you, enable you and not let you down.
There is no substitute for experience. If you intend to ruck, then go out and Ruck! Join the folks at GORUCK when they come to your town, and remember "...runnin' ain't ruck'in...". I can not stress that enough. You may be able to run ten miles, but, put on that 40 lb ruck or heaven forbid an 80 lb or 100 lb ruck and you will quickly be humbled.
Train like you will fight. If things go bad, and you are fully acclimated to numerous miles with a 40 lb ruck, a short ten mile walk without it will be a snooze fest for you.