I currently carry a Contender in 45/410 when I fly. But realistically that is not a very good combination. Have been thinking about carrying My Savage 30-30/12ga, but it is so heavy. Also the 30-30 leaves something to be desired in the energy department. Could a 45-70 barrel be worked to shoot 410 shells? I know when we were kids my brothers and I used to shoot 410s in an old trapdoor 45-70, and we're all still around to tell about it.