Fred,
I know of one person already going for a .375 flanged on an original martini action. 9.3 x 74R might just work - or not, but I think it would work in the Greener GP action size. I have a cartridge here somewhere, I'll take a look with one of mine, but that round is rather straight and long...
And as to plans, well.... I know there is someone with plans to build new Martini's, but those plans are on hold for the moment - He was going to start with a small-action one, then add 2 other action sizes (mid and large), all according to the Francotte patent. I haven't yet been able to locate any drawings yet, only some patent information, so I'm afraid reverse-engineering is the only way to go.
The chief advantages of the Martini are: 1.strong, 2. safe, 3.simple. Just count the components and compare to e.g. a Ruger #1. Of course, the components have to be machined quite carefully, as the iterrelationship is quite important. Maybe you ought to take a look at the LoC instructions of the Brit army for replacement and repair of the Martini's - lots to learn there...

I went to Atlanta Cutlery this week, and bought one of the P-1871's. I posted a report on the African Hunting forum. Here is the link for anyone who might be interested. Nepal Martini

Jim

Thanks for the info. I am leaning towards the 375 Flanged if I proceed with this (big) project. The 9.3x74R does appear to be too long for easy operation in this action. I agree that the simplicity of the Martini is its huge selling point for me - plus it is a strong action from the extra research I have been doing.

I did manage to find one place that has armorer's drawings for the Martini:
Martini Drawings

I sent him an e-mail asking for more details, and here is what I received:
Some of the drawings are ex-MOD Pattern Room and Inspectorate, so dimensions
are included in the drawings, for checking and inspection purposes. My SAIS
#15 (.450 & .303 Martini Rifles & Carbines) has all the component parts
illustated, essentially drawn from the armourers and inspection charts.
However, dimensions such as apply to action bodies, breech blocks, &c. are
not indicated. I think you best bet would be to use a certain amount of
each, what drawing dimensions are available, with a certain amount of
dimensions taken from available rifles and/or parts.

So, it looks like the hunt is still on. The only real stumbling block is the action itself. I have found parts supplies, so one can buy all the internal pieces as replacement parts - but that still leaves me needing an empty action to put them all in! It does save me the trouble of machining and heat treating all these components, though. All I need now is an accurately detailed manufacturing drawing for the action body. It should be fairly simple to draw it in my CAM system - the lines aren't that complex.
maxman

Nice purchase! I read the report in the African forum earlier. I'd be happy with that one. It looks like it's in pretty good shape for a shooter.
maxman