The 6.5x55, 7x57, and the 8x57 are all under rated. Agree with Ben and the X factor in the minds of most Americans. I took my 7x57 to Africa and killed 10 head of plains game at ranges to 450yds. One of my hunting companions took his 8x57 to Africa this last year and shot numerous plains game at ranges up to the 450 yd mark. Gemsbuck , kudo, are elk size animals, and they go down with the X cartridges as well if not better than fashionable belted mags. I would not hesitate to take a 6.5x55 to Africa and shoot plains game. Actually, under rated is truly a an under statement of understanding in this day and age of belted magnumitis. Have no experience with the 9x57, but I would bet it would also be a super ctg. Just because a cartridge doesn't sound American------well you know!