If you are talking about the 338 win mag, then Yes it will gain you a considerable amount of distance. The 338 win mag will lose too much velocity with the heavier pills over the Lapua. A 338 Lapua with the 300gr Bergers will get you to 1500 yards +. Even the 338 RUM will out perform the win mag for distance.. Either one of the two I mentioned are in another class compared to the 338 win mag. Don't get me wrong the win mag is a good close to moderate range heavy hitter but there are much better options available today..