OK Tinker, I'll accept your judgement on that, but my own beliefs probably parallel DoubleD's: Henry rifling for paper-patched lead, Metford rifling for jacketed with black powder.

My own favourite Martini is much less ambiguous: it is an Army & Navy sporter, buff-horn forend-cap, full-length engine-turned rib with banners, and enfield rifling. Shoots extremely well, fast-twist barrel for the 215-grain bullet. Magic!

...just reminded myself to take some better photos of this marvellous rifle next time I bring it out to play!

Have you checked the twist-rate on your mate's rifle, tinker? Most (if not all) metford-rifled barrels would be set up for the 215-grain round-nose bullet. This might go some way towards explaining the ho-hum accuracy...

Hope your friend's Martini brings you as much joy as mine have, tinker!