for some years I had a (wooden) Rem.700-safari (wooden) chambered for the .416 RemMag in regular use. Overall it was a fine rifle, though it had a very slow barrel with a rather sloppy chambering and mediocre accuracy.
As I changed the barrel with a lothar-walther barrel I could gain instantly 100 fps more with same loading data as before but combined with superb accuracy.....
The change of the barrel was not expensive and should be thinked of if you get hands on a Rem.700-safari....also, had a three-position-safety-cocking-piece that secures the bolt instead of the trigger (as found normally on the 700 Rem).