Free: Contests & Raffles.
Why not sell that rifle, and get you a light weight 300 wsm? Just a thought.
Id get a lighter contour fluted barrel and a light weight stock. Get a reloading manual and find a caliber you like that uses the same bolt diameter as the 300 mag... you could go with 7mm or 338 vary easy...24in is going to be the barrel length with any magnum if you want shorter you need to go with somthing else. Im building a 6.5lb 338 win mag right now for the same reason that you mentioned above.. you can have your action skeletonized to save some weight as well...