The stock is not particularly heavy just that the barrels are exceptionaly light. Modifying the central rib is not an option it is integral to the gun and also the aforementioned sighting system.

Regarding the action and the pressures that it can stand I am in no way a gunsmith therefore I can not comment but I assume that it would be safe with modern loads. That is something to be tested when the 45/70 finally comes on the scene.

Either way we all should be careful in not trying to make this into something it isn't. It is a fun, cheap double rifle. Take it hunting, shoot some targets, enjoy it!!!!