First off welcome to LRH!!!
The 112 BVSS rifles, along with most savage rifles shoot far better then many would expect.
For an entery level rifle for long range shooting this is a quality, very affordable rifle that will serve you very well. The good news is that the rifles shoot very well on average and are relatively inexpensive to get into.
The bad news is that they are not the most pleasing rifle to the eye if that is a concern to you. The rifles generally look much more attractive after they have been shot and you see how they shoot!!
There is certainly nothing wrong with the Mk4 scope but you really do not need to drop that kind of cash to get a quality long range scope. Even some of the Leupold VX-3 Long Range scopes will serve you very well and save you $400 compared to the Mk 4.
One scope I would recommend you looking into is the XOTIC USS scope that is offered by SWFA.
Here is their web sight:
I personally feel this scope is far brighter and clearer then any Leupold on the market. They also have the reticle on the first focal plane in the scope which means the mil dot system stays consistant with the target though out the entire power range so you can use the system to full effect on all powers making it an extremely versitile scope.
It also has over 100 moa of vertical adjustment so you would easily be able to take the 300 Win Mag out well past 1000 yards with no special bases needed.
They sell for $800+shipping which I personally feel is a steal. I would pay $400 more after using the scope I ordered in. Very impressive optical system.