I have a small ring (I am assuming this) Martini Henry in I think it was .320/.250.

It was a Victorian Colonial military arm. I plan to keep it as a wall hanger, however I am wondering if the action is suitable for a custom rifle of some sort - ie I may look for another one if this is the case.

Does anyone have any experience with customising these rifles, and what sort of cartridges are suitable for the action?

I'm thinking of cartridges such as a .17 K-Hornet, a .22 Hornet, a .22 Hornet Improved, .221 (?). What about some sort of 6mm?

Thanks for any information.