The shell may fit in the chamber but your problem will occur when you actually pull the trigger. The folds of the crimp have to open up to let the shot and wad go by. If there is no place for these to go you create a pretty good constriction right at the end of the case. Can't remember what the diameter of the case is verses the shell diameter but unless the petals are less than .042" thick (.452 -.410) it could be a major problem. The chamber area of a 45/410 is usually over 3" long which is why the 45LC accuracy usually suffers. If you used full length brass 410 cases with an overshot wad then it might work. However your cases would probably have a funny bottleneck shape where it stretched into the chamber. I think I would just get a 45/410 barrel and not worry about it.
Bill R.
