Don't know the answer to that, lancaster. It depends on what a person wants.
Here, in Canada, even simply possession of exploding bullets is frowned upon. The ML should
develop much higher MV (maybe) - but will that overcome the much larger, heavier conical of
the 8 bore?
The 8 should be the more powerful, however much depends on what a person wants.
I personally would be much happier with the multi-barrel set on the percussion double.