I have both the 6.5x55 and 7x57 , both are 20 inch barrels, they shoot very tight groups with 120-140g cartridges if I do my bit properly! 7x57 is my preferred rifle of the two and used it on muntjac to red stags and also wild boar in Germany and Hungary, would definitely be the last Caliber that I got rid ofI would choose the 308 (or a 7x57?) if buying a new barrel. 308 works well in shorter barrels and is easier for developing subsonic loads. although I like more the swede.
