Actually, you can make a pretty nice 303 out of the Martini-Enfield. I have 3 of them that were made in 303. If memory serves, when the 303 was first developed (in black powder) it was for the 303 Martini-Enfiled.
These have wonderful triggers. One could take off the military wood, install custom wood and have a nice rifle without having to bubba the rifle. Think of it as the great grandfather of the Ruger #1.
I have one that had a shot-out barrel which I replaced with a barrel from a NºIII. The trigger is VERY stiff, though (unlike my .310 Cadet). Once I get the new house finished and have a proper workshop I'm going to have to spend some time working on that trigger. I suspect the engagement angle of the sear and tumbler may not be right.
The Martini is one rifle that I wish one of the Italian replica mfrs. would start making. They just ooze history.