Odd, I fly United often and the bad legs are most always the regional carrier's fault. Checking guns in Boise, Idaho, Rapid City, SD, Wichta, KS, has never been an issue other than the airline personal wanting to know about the hunting trip. They see LOTS of guns, flying with one shouldn't be an issue if you follow the rules. All my international gun totting trips have also been without firearm issues - there was the one time I didn't have a permit to import my ammo but that was easily resolved.
