For extended treks the internal frame pack should have a volume over 3,000 cubic inches (50 liters), but less than 4,200 cubic inches (70 liters).
The conventional wisdom used to be that external frames are for trail hiking and internal frames are for off trail hiking.
Most of our hiking is on trails, but the majority of Scouts and adult leaders prefer the internal frame and these have become the most commonly available packs.
(Some ultra light people do not bring any clothes except what they wear.) Each Buddy Team: Two-man tent (count the stakes) and ground cloth (optional) Group Equipment – Distributed among hikers Water filters – Water jugs/bottles/bags Stove and fuel bottles Large and/or medium cooking pots Cook Kit: spatula, serving spoon and/or utensils, measuring cup, camp suds and sponge, bleach, scrubber, Purell Stuff sacks for food Bear bags and rope (50 ft ¼” braided nylon rope, 50 ft 1/8” parachute cord, 2 ft 1/8” nylon cord) or Bear Canisters in some areas Repair Kit (sewing kit, small piece of cloth, safety pins, wire, pliers or Leatherman, superglue, tube, O rings for filter, rope, and more) Troop First Aid Kit (check it every hike) Permits, Maps, Medical Forms Pack List Weights in pounds No one should be carrying the “High Weight”.
It is listed so you can see how much you can save if you are careful.
There is lots of discussion about the proper amount of weight that a boy can carry safely.
It varies wildly, depending on the attitude and strength of the boy.