I have owned my 300 whby for 6 years now and have killed 5 elk with it. All the animals where one shot kills from ranges of 80 yds to 328 yds. I use a 180 grain weatherby factory barnes x bullet. The ballastics for this combo are fantastic. It is a very flat shooting gun for a magnum rifle that also delievers good down range energy.
You wouldnt go wrong with owning that gun.
The 300 Weatherby definitely has the edge for the type of hunting you indicate. Your effective range will be further with it than the 338 win mag, and it is still going to do just fine on moose at closer ranges.
If you shoot it well, there's not much you can't do with it on this continent.
What do you do with those empty nylon feed bags or dog & cat food bags? Can you say recycle? I use them for target practice for the youngsters. Take your empty shopping bags, stuff them into an empty nylon feed bag. You can also use old clothing or rags, (but put them in the bottom so it doesnt get top heavy). When your bag is full, fold the top over, punch some holes into the top and zip tie the top shut. Paint, draw, paste, or have the kids decorate their new target. Set it out 10 or 20...