I'm considering a 7mm-08 or .308 in some sort of "mountain" rifle (stainless barrel, synthetic stock, etc). I've noticed that a number of rifles lighten their weight with shorter barrels. E.g., I'm looking at a Howa Alpine (as well as others). The Howa sports a 20" barrel. How much of an effect does this have on ballistics and accuracy? Also on felt recoil. I realize the latter is quite subjective. I like the idea of a lighter rifle that I might carry for days but shoot only once. OTOH I want that one shot to be reliable. Will my 20" barrel significantly deviate from a manufacturer's published ballistics? Thanks...