It's just a push feed action.
Magnum brass for any caliber is going to be very expensive.
With that slightly-bent analogy in mind....
Rechamber for the 300WinMag and be better off all round.
might be a perfect candidate for a Ackley improved 30 06.
You can build pretty much anything you want off the action.
That rifle's receiver won't handle the .300 H&H round as it's too long.