I'm a really big fan of the 375 H&H especially in a nice short fairly light weight hunting rifle. Mine is a winchester 70 w/20" barrel and all the excess metal taken off for an over all weight of just over 7lbs loaded with a scope. If you want something for long range shooting 300+ yards I woudl go with the 338 RUM. It is a long range powerhouse with 225gr bullets at 3140fps, settle it in an 8lb rifle and you have a serious long range hunting rig. The 375 RUM is a great round too but in a light enough rifle to be practical it does tend to kick a bit. The 300 RUM with 200gr bullets is another good one for longer range shooting.

I guess it all boils down to where you will be hunting. You can definately do it all out to 300 yards with a short 375 H&H, but when long range moose/carabou/sheep hunting come into play where shots over 300 yards are very probable then its hard to beat the 338 RUM, also the rum will do just as well at 50 yards if you use preium bullets. I like the 225gr accubond with retumbo for 3140fps, very accurate and flat shooting.

If you go with the remington 700 there are a few mods that can go a long way to improving reliabilty, a sako style or better yet AR15 extractor and double plunger ejector will make them just about as bullet proof as you can get. Plus its a pretty easy conversion to make the 700 a switch barrel in 338 RUM and 404 jeffery. Would make for a very interesting combination.