This isn't one of those which is better posts. Each is a great cartridge. I own a 7x57, but have owned two 6.5x55s. Although it may be slightly better than the 6.5x55 on most of my hunting (wild pigs w/175gn,) it's not as flat shooting as the 6.5 w/129s. Maybe its just me, but in reading this board the 6.5x55 seems to be more popular. Why? My question has to do with tradition. It seems to me that the 7x57(275) was the traditional stalking rifle cartridge. It was also by two of the greatest Brit hunters of all times, Bell and Corbett. Thanks for your opinions, capt david