I've shot (for record) a 4.1" group with the 6.5-284 in 1K BR
My hunting 6.5X284's never could do that.
I've shot 1" groups at 550 yards with my huntnig weight 6.5-06's
I really don't think accuracy goes to one or the other. I feel the accuracy is in fact directly related to this.
The smith
The barrel
The hand load
The nut behind the wheel