i'm not much help to you, the only ammo I tried was the factory 127gr's, the short time I played with a 6.5-300. That load really impressed me, and would have no problem using it for anything I would use the 6.5 for. The 140's on paper look very similar in performance as the 140's in the 270 Wby, so in theory they should work good also, on game. As for accuracy only your rifle knows that.
Rob