I think that it would be a custom proposition. With a lot of re-engineering.
What has me thinking is the sights, gas cylinder, GC lock, all that would have to be custom made to the larger diameter barrel, and the op-rod offset would be lower, more than likely causing contact issues with the lower band, necessitating a custom one
The center-to-center distance would increase quite a bit with that much increase in the barrel O.D..
Then, what kind of issues would you have with the change in relationship of the op-rod to the receiver tracks. You'd more than likely have to re-think the op-rod bends.
It could be done, but not cheaply. A BAR (Browning sporting rifle) would be much easier. Start with a .300 or .338 mag....
