My Bug-Out-Bag is an Expedition class North Face hiking pack. The reason is simple. I mentioned in another post that for many years I have been an avid hiker and have made long excursions into back country areas where firearms weren't even permitted and I certainly wasn't able to pack enough food and water for that whole time. Those are things at some point you have to acquire along the way.
The particular pack I use is an internal frame pack with extremely good, breathable padding in the back and on the straps. BTW, a waist strap/belt is crucial when your pack is weighing in at 60-80 pounds and you're planning on walking 10-15 miles a day with it. If anyone is looking for a good pack, I wouldn't necessarily put you onto a specific brand but I would encourage you to consider these types of packs especially if you are thinking about it being necessary to travel by foot and I always consider that to be a possibility. To me the term Bug-Out-Bag has always been based on the premise of walking but that was mostly due to growing up with a guy who trained special forces back in the early 70's. His philosophy was to always assume that you would need to get by with what you could carry on your back. Anyway, the most important tip that I could pass along is that ordering a pack off the Internet is not your best option or at least not initially. Go to a good outfitters shop and let them fit you for a pack if you're really serious about it. Then if you want to do some price shopping, you'll have some idea about what does and does not feel good to you. It's more important than most folks would believe.
These packs can hold a lot of stuff and I have lived out of one comfortably. If a need were to arise, I already have everything I need to get by in there and the addition of being able to strap a .22LR to the side of it and throw a brick or two of ammo in there would be welcome but not required. You will not want to carry around a well rounded pack along with three or four guns and 2000 rounds of ammo. It's just not reasonable. I'll try to get into what is in my pack on the other topic that's been started for that. Anyway, once you've assembled a pack, I'd encourage you to find a nice wooded area and take a little walking trip for a day or two or whatever you can spare. And don't just walk a mile and unpack it and set up camp. Plan a trip that requires you to move around. You'll find out quickly what you can and can't live without. :2c: