OK, I am looking at options to buying a new rifle for this application.

I have a Stevens 200 LA (currently chambered in 25-06, center feed, internal mag. Completely stock from the factory) (I did tweak the trigger to make it acceptable ) What would it take to make this rifle feed a 6.5-284? Swapping the barrel is pretty straight forward, my concern is with the internal magazine, and what it will take to make the new cartridge feed properly. Your help is appreciated. Thank you! :)