That would be a very cool package to show up with at camp. I like it!
Yeah, it would be and if I can sort it I may well try it.
I already have a large frame Martini Enfield action and the extractor is already correct for 303 Brit.
40-60 Maynard can be formed from 303 brass and so it would be just a case of getting a bbl chambered to it and spin it straight on.
The only drawback is that 40-60 Maynard uses a 300gr .417" pill and so I'd either be forced to use a .416" cal bbl which would be pricey to buy bullets for and which the rifle would fire too slowly for them to expand properly or to cast them myself.
Another option is to size the neck down to .410" cal so I could use 210gr pistol bullets.
Or I could get a .411" cal bbl and shoot 315gr 405 Win pills in it.
In the end it's about practicality.
The ultimate I suppose would be a bbl in 577/450 instead of 40-60.
I could shoot 45 cal pills and since it's a nitro proofed action you'd have a rifle with more oomph than a Marlin loaded 45-70.
Mind you the cases would be pricey, tougher to re-size and I'd have to change extractor every time I changed the bbl.
That means pretty much stripping the rifle.
Not so fun!