I have done alot of research on semi-automatic rifles, in regards to semi-auto hunting rifles, NOTHING can come close to the browning BARs, mostly everyone that owns the remington 7400 is not very happy with em. I currently own a 7400 but I only use it in the range, its fun as hell, accurate too, but I don't think its a "better" rifle than my BAR.
those remington 750 are new guns, not many people own them, so their reviews are still a bit "iffy". I would wait a while and see what people have to say about them. Now if your looking for a powerhouse caliber in a semi-auto, you do what I did and get a browning BAR in 338 win mag.