Should shoot 198-200 gr. well.
If its all original I would think twice before I replaced the barrel. Original German Mausers go for a premium, especially if they are all matching. If its not, go for it.
I love my 8x57mm's. I think they have an unwarranted reputation as being inaccurate, probably due to shooting too light of bullets. Most (except for Turkish I believe) were designed to shoot 196-198 grain projectiles.