my gripe is all those efficiency claims
its not anymore efficient, your claim is 2860 fps with a 210, vs the wm with a 190 at 2900 with 9 gr more powder
1) a 300 wsm will not run a 210 that fast as it comes from the factory due to longer seating length of the long action box mag and perhaps a longer throat, so to shoot a 210 in a factory wsm your using up a lot of powder space for bullet storage.
2) also your wsm has a 29" barrel
3) the custom barrel is faster than a production barrel, at least every one I ever chrony'd was
my 6.5 gibbs will flat outrun a 264 win mag with 9 gr less powder, but it has a 30 " barrel, that 1/2 foot of barrel doesn't make it efficient.
you will always hit max pressure in a smaller case using less powder
Inherrent accuracy
once you full house customize a rifle, inherent accuracy is a moot point, I have a rifles built by some world class smiths, they have case capacities anywhere from 20 couple to 122 gr of H2o they will all shoot bugholes from the bench, very little difference in group sizes which cannot be proven to be related to inherent accuracy
RR