We talked about quite a few of the issues in the periphery of the OP’s question, years ago here: https://www.lightfighter.net/t...-3rd-line-gray-areas.
I agree with Tankersteve about defining patrolling, the environment it is occurring in, and the other missions being conducted when not patrolling. Are you typically conducting movement to contact, deliberate attacks, raids? SOCOM and Rangers can develop mission-specific packs but GP forces simply do not have that option.
I also agree that different occupational specialties have different requirements, but the pack can be built to adjust to their needs with a little careful thought. I don’t think most other GP troops need a dedicated pack, besides maybe the medic.
My thoughts on your questions circle back around to ALICE and an exploration of why we went away from ALICE. Do a deep dive into that and I think the way ahead gets illuminated pretty easily. You’d should also procure both a medium and large ALICE bag and the frame, and just lay it out in front of you and look at it for a while.
-ALICE did not have much modularity and you were left with the pouches as they were.
-Mission-critical gear often ended up hanging off the bag, and could get ripped off when snagged on vehicle edges, vegetation, etc.
-Your load could turn into a dynamic load very easily, making the crappy straps a chore to use, so the straps would need more attention. It looks like Crossfire has minimized a lot of that with the new means of bag-to-frame interface. It just needs to be simple and grunt-proof.
-You could take the medium bag off of the frame and use it paired with only the straps, which was sometimes great when you weren’t wearing a flak jacket and were only carrying a lighter, mission-specific load. I don’t think the answer has to be a hard choice between external or internal frame (see more below).
-The basic volume of the medium ALICE bag is probably the sweet spot for patrolling. It and small ALICE seems to have worked ok in the Vietnam environment.
-The 40 liter medium bag forced you to be judicious in what you carried. Sure, the packing lists were often driven by some silly SOPs, but 40L, no matter the number of batteries, rations, ammo you need to carry on “patrol”, was a good baseline. It could be expanded to fall into maybe 50L (about half the delta in volume with the 62L large ALICE) size, but don’t just make it 50L without some deliberate thought as to why.
Because ALICE was so good at the mission, maybe it just needs updating. A good number of companies have done a respectable job with their attempts at an update. My recommendations would be:
-Adding curvature, a chest cinch strap, and legitimate padding to the shoulder straps.
-Adding a sleeve to the back of the main pocket so a stiffener can be slid into place when the bag is taken off of the frame. This would provide shape and form to the bag and minimize contents shifting when the user needs to secure ammunition, a radio, etc.
-Adding durable but easy quick disconnects so you can get the bag off of the frame without a lot of fuss when preparing for a different mission.
-Adding a reasonable amount of PALS webbing to increase performance.
-Adding a tie-down grid on the back of the pack, like the RAID’s system, so equipment can be lashed into place.
-Making the frame adjustable for length.