This is the largest rifle case you can use for checked baggage and not pay an extra $75 - Pelican 1700 Protector Long Gun Case

After some extensive research I found this case from Pelican to house my Kimber 84M when traveling out west to hunt. Please note, a rifle will not fit unless you takedown the stock from the barreled action, BUT, if you do the case is wide enough to fit both parts with the action scoped. There was room enough to make a cutout to hold a box of bullets and the whole thing weighs about 25 pounds. As long as your checked bag is under 62 linear inches and 50 pounds it will not incur a dreaded $75 "oversize" baggage fee (on top of whatever your airline is ripping you off for to check the bag in the first place). I feel confident that my very expensive rifle will be safe from baggage handlers in this case.