Thanks for all the feedback!
As far as my thought process is concerned, see "pros" No. 1-4 in the first post in this thread. :grin: Of course, as some of you have pointed out, it may be that mil-surp ammo would not function well in my proposed rifle.
I'm figuring out how to proceed (work is crazy and I've got lots of projects around the house so this is project is not front and center).
(1) I may see if some disappointed person wants to sell me a 7.62x39 barrel cheap. I would them either have a gunsmith do the rechamber or do the rechamber myself (I'd have to research what's entailed with doing it myself. I'm not a maschinist. If it involves much more than turning a reamer by hand I'll probably pass on doing it myself). This would also involve fitting a rifle barrel to a receiver. Or,
(2) I may send a rifle to the factory for both a 7.62x39 and a .308 or 30-06 barrel. Again, the 7.62x39 barrel would be for the rechamber. This approach defeats the idea of economy, but I'm still insterested to see how a rimmed-mid bore cartridge (something more potent than the 30-30) performs in a handy. Plus, if mil-surp ammo doesn't work out, it seems like the 54R would be a dandy for reloading. Or,
(3) I may scrap this idea entirely and just purchase a .308 or 30-06 barrel or complete rifle.
What to do?! :?
I still think this is at LEAST an OK idea. IMO a 7.62x39 barrel that won't shoot cheap ammo is near worthless but a 54R barrel that doesn't like mil-surp would still be worthwhile for handloaded ammo.