The bigger the bore, the less 'fussy' they can be as to different loads. A bit of load development usually pays off though & makes the owner smile.

I always work to find the very best accuracy a gun will give, usually to the excess and although I hold that it isn't necessary to have a gun shoot under an inch, it does make one feel good - especially when the bullet makes a descent sized hole by itself. A 1" group with a .416, similarily to a .45 cal. rifle, will just be a single hole wit 5 shots. Nice to see.