My son flew with his 1911 last month
S&W. Washington to Arizona. Gun in case, case locked. He was there, declared gun, remained available while TSA arrived, opened case, yada, yada, locked it when they were through. Case went into his luggage. Arrived Tuscon, no trouble.
If you are not there, they will cut your lock, then they will not put your gun on the plane (because they cut the lock), so be there when you check it in, and stay there until they are all done. Then lock it, and keep the key.
Yes, its a hassle, but you can still do it, and be legal.