For many years , any 6.5mm cartridge was treated worse than a red-headed step-child.
But as them wiley Scandanavian hunters/riflemen know , the 6.5x55 Swede and their long freight train bullets with their high SD/BC , will penetrate a big ol' elk or caribou completely and drop it like a bolt from the blue with 1 well placed shot from a LONG way away. With the import of all those Swedish Mausers , there has been a lot of R&D on the 6.5mm and quite a few new bullets.