Have you looked into building something off of the new 375 ruger. its pretty impressive. and if you wanted a longer barrel like you were talking about it would really scream. the brass would be availible. plenty of bullet sellection. you wouldnt have case diameter issues. I dont see it becomeing HUGELY popular so you will probably be the first guy in deer came to have one. even if you put it in a 22 in barrel (factory rugers are only 20) you would have one awesome brush gun. could be a great bear gun too. Heck if you dont build it, I might