I frequently carry a m70 fwt in 7x57, my youngest son's favorite firearm is his m70 fwt in 6.5x55. I've got a wildcat 6.5x308 that my dad built in the late 70's, amazingly enough it's dimensions exactly mirror a 260 rem, so that's what it eats. I think that's about it for non mainstream cartridges for me, I do prefer the classics though.