I have a G2 contender frame and I bought an old style 10" .45/410 barrel last year. I haven't got around to using it yet but I am going to take it out this week. I was wondering, is it safe to shoot 3" .410 shells in this barrel as it is not marked. The shells slide in freely so I would think they would be fine however I felt it best to ask here first. THanks.