RLI,

"I have heard that this rifle can be rebarreled to 9.3x62"
This has actually already been done in the last 3 months.

"What would the pressure levels be compared to the .270 Win.?"

Probably a lot less as the .270 Win is one of the HOTTEST "Standard Factory" rounds available
- without checking I think it generates areound 55,000 psi.

500 Nitro