I've reloaded for a while but have never really got into really accurate stuff. I am reloading 6.5CM 120gr GMX's right now. Hornady a book says that the oal for that bullet is 2.71 but the max for the 6.5CM is 2.8. How much difference does it make if the bullet is seated above the 2.71 but not above the 2.8?