A couple of years back, when I was gearing up for a precision rifle course
, I picked up a 5.11 Rush 72 pack
. I needed something to hold everything I might need while out in the desert shooting during the day. (rangefinder, ammo, spotting optic, log book, tools, GPS, wind meter, hearing & eye protection, rear bag, jacket, lunch, water, etc.) With a shooting mat and rifle case in hand, everything else needed to fit in the backpack. I also used the backpack as my front shooting bag.
It did everything I needed it to do and it worked well. I was very satisfied with the results.