Was thinking this over a bit.... I train and help instruct positional shooting in a couple schools each year. You didn't ask about anything more than a rear bag support but something you may wish to think about is the use of a tripod. A fiesol 3342 with leveling head and arca clamp is around 3 lbs and serves as a platform for your bino's, spotting scope, front support, rear support, and a club for angry beavers. Yes, it is additional weight but with the way this unit works you could easily eliminate a bipod (you can easily shoot prone with this tripod) and rear bag if you desire. Properly set up balance point with a arca rail and clamp and some practice you can make 1000 yard shots off the tripod without rear support. I prefer to use my backpack, a trekking pole, or a stick for rear support. Tons of options on how to use tools like this if you are willing to spend the money and time on it. I have killed a bunch of coyotes off the tripod, a few deer, and wolves. Below is photo of my set up after shooting a wolf at 515 yards and chasing that pack down 3 miles in the snow. I really didn't have a prone option, my back pack would have been ok for front or rear support but in this case I went with the tripod, shooting stick rear, and it was perfect. I was pretty excited and that set up is rock solid.