I fail to understand why anyone loads for accuracy in hunting loads. I'll bet I've killed 100 deer with a .243, and the only thing I gave a damn about was that the bullet held together at high velocity. A .243 needs all the velocity it can get, and since it's light you shouldn't be shooting beyond 300 yards since the round doesn't have the kinetic energy to assure a kill at long range.
You should load for terminal performance, period. A 2 MOA group means that at 300 yards your slug will land within 3 inches of your crosshairs. What more do you want?
By your logic, why should anyone even try and attain any accuracy, but simply load to the max velocity and go hunting. Most hunters cannot use the accuracy a factory off the shelf rifle can give in the first place. They simply do not put enough rounds downrange to get anything out of it. This said, there are folks out there who DO care about how much they can get, and strive to get it all.
Also a 2MOA group at 300yds is just a tad over 6" and I sure as hell want all of my rifles to doing MUCH better than that. But your right, it should hit within 3" of your cross hair, but in which direction, and that DOES make a difference.
For my money (and I'm very experienced with the .243), nothing beats the 100 grain Nosler Partition. Most of the deer I killed with a .243 were with NP's. I never once recovered a partition. Not once. The .243 with a high velocity NP is pure deer poison with an exit wound that's damned near fist sized. I always loaded to max velocity even though that was never the most accurate.
I won't doubt your experience, and I sure won't say anything bad about a Partition, but it is not the end all bullet for every situation or need. It is certainly not needed for a whitetail nor an antelope, or even things a bit bigger. What is needed however is to be able to put the shot where it needs to go and not
HOPE, is the one which will hit where I aim or is it the one which is going to be off to the right, the left, up, or down, by 3" or more.