I know that in most cases a base of operation location will not require the 72 hour gear to be packed in, but for those who do pack it that way just in case, what type of pack do you use? Alice, internal or external frame backpack, or what? If a backpack, how many liters/cubic inches do you use/recommend?
In days gone by I fit all of it (plus) in a medium ALICE and then in a CFP 90 (minus the tent).
Personally, I use the GI issue MOLLE pack with sleep system carrier and side pouches. The main compartment holds everything needed for 72 hour gear, including food, and I use the side pouches to carry extra water. My day gear gets strapped onto the outside.
No matter what pack you use, whether it's commercial or government made, 3000-4000 cubic inches should be plenty. If you need more than that, you probably want to re-evaluate your packing list. Also, make absolutely sure that the pack has nice, thick shoulder straps, a waist belt, and the seams are of good quality. When used properly, the waist belt transfers the weight of the pack from your back and shoulders to your hips. May not seem like much of a difference, but trust me, you do not want to be carrying 50+ pounds without one. BTDT.
I like the MOLLE pack because all of the main components are attached to the frame, but not necessarily to each other. This takes some of the pressure off the main seams, helping your pack to last longer. That is if you don't mind if your pack is wider than you are. ;D
I use my ILBE Main and Assault pack. Prior to that it was a medium ALICE pack. I have gone through many packs from camelbak BFM, Motherlaod, Spec ops brand. But Alice beats them all.