Like a lot of blokes, I can't afford a top of the line double rifle ( or any double rifle for that matter

)but as I tend to build every thing I want ( and usually cant afford ), I thought I might have a go at a double rifle from a shotgun. I'm thinking of a bit of a practice run with an old Remington mod. 12 that I have. It has no stock or fore end and its already had a flogging so I don't have much to lose except some time and hopefully gain some experience.
Now to the point of this post.........is this action strong enough to build a double on ? if so,what? I was thinking of , in order of power/pressure,....30-30, 35-30, 303B, 7.62x54R and last 444 or 45-70....any ideas ??

Roger