There are so many 6.5, 270, 7mm cartridges that overlap performance-wise. I think that in practical terms, there really isn't much difference between many of these cartridges in the field.

I remember shooting with a friend who had a 6.5x284 that he said was the "cat's meow". The performance seemed to be the same as the 256 Newton. Of course, the 6.5x284 had a 1/4" shorter bolt throw - whatever that really means - not sure the importance of a slightly shorter bolt really is.

Well, I do like reading about new cartridges and new guns.