Make a smooth bore out of a rifle?

[Clovis]

Sometimes I thought about boring an old SMLe barrel out for a shot gun and putting it on a drill receiver or something just to mess around with.
Thank god he created rimmed cartridges to make stuff like this easier.
I have a Smooth bore Martini barrel that should be getting used for something too instead of just sitting around doing nothing.

I'm sure you know the Indians already turned some of their #1Mark IIIs into .410s but it deserves a mention for this thread. Mine was not converted to modern .410 shells and is a reloading process to shoot. It works out fine, but tried as suggested to load the .45colt shot loads and it is a no-go as the original chamber is too small.