last time i flew southwest the only airline i use as they are non stop from phoenix to buffalo and they never charge for my gun. matter of fact last time i flew with two check on bags my muzzleloader and a cooler with 50 lbs of deer meat and the girl didn't charge me any extra!!(maybe because her dad hunt's too)? but the gun's are pretty easy to fly with the only issue is getting someone that understands muzzleloaders because you have to show them your gun is unloaded so if you have a traditional rifle it's tough to prove if it's inline you can have it taken apart before you get there and store the parts in baggie in the gun case or like me i put them in my carry on backpack thinking if they stole the rifle (super 91) they would not be able to do anything with it unless they knew what they were doing!