I should give away a little more detail on the reasons behind my question.
I am going to start shooting with a .338 win mag, which will be my go to big game and steel shooting gun. Now, realistically I can, have and will make shots to about 700 yards max in a hunting situations. That has been with a 6.5-284 mostly, and a .300 win mag.
To be totally honest I'm not sure I need to go much further, because my preferred hunting style is not the long range that some guys here regularly do. I don't tend to go out and look for a long range shot, but I like to make them when presented, especially if there is no other option.
But as I was looking at the ballistics of the 300 grain Berger VLDs in .338 it looks like with the .338 win mag you can start at 2400fps, and at 1500 yards still have around 1000 ft/lbs of energy, while being somewhere in the 1200fps range. Much lower than anyone claims a bullet can expand.
I would guess that that is enough residual energy to push that slug through a deer, which, providing vital organs are hit, and maybe even shoulder bones, be enough to kill.
The reality is that this thread makes me realize that the .338 win mag, is capable of killing beyond the ranges I will ever shoot at.
If the . 338 win mag is considered to be around 250 yards shy of the Lapua mag, in terms of performance, then that means I have a lot of practising to do before I run out of range.