POI changes between 2 shooters

[WildRose]

Most likely just a difference in how each of you are mounting the rifle, cheek weld difference is the most common.

 

[MudRunner2005]

Browning X Bolt Hells Canyon Speed in 300 WM. After going through the load development and getting under 1/2 MOA at 100 yards, I took the gun to my buddy's farm to see how it shot at 300 yards and beyond. So I set up a prone shooting setup on sandbags and I shoot a sub 1.5 inch group at 300 yards. Then I let my buddy shoot it and he lays down a 1.5 inch group at 300 yards, except his group is centered 4 inches from mine. (BTW, Parallax knob on the scope was set at 300.) So can someone explain the reason for different shooters having that much of a POI difference? I am talking about more than just saying "different shooter....different results". I accept that this can happen, it's just that I don't understand it.
Thanks

Different cheek welds and different eyes, different grips, different shouldering, also like JE said, parallax adjustment can be different for different folks.

I have a buddy who could shoot my rifles dead-on where I shot, as far as elevation goes.....But he was always about 3" to the left or right every time.