It will help but an antique design can only be helped so much. The Mauser is fine where accuracy isn't the primary requirement. For me anyway a .243 should be very accurate. The reason the Remington 721 (later the Model 700) was invented is because Bench Rest shooters couldn't get great accuracy with the actions available at that time. Nothing has changed.
The Hornady A-Max will out shoot the Bergers.
