Just a thought: while it adds a little weight, a 16" bull barrel gives you a lot of flexibility as far as distance accuracy in a shorter, handier package. If you are going up and down the side of mountains, go with the shortest, lightest 308AR you can find. A pencil barrel, etc. etc.. It Sounds like you want something fairly mobile, but those pictures would indicate you also want something with high accuracy potential. You won't lose anything with the 16" barrel versus a longer one until you get well past 500 yards, and I find the heavy barrel makes for a really secure platform for longer shots.