Past a certain point, I view obsessing over group size as being counterproductive. I have never fired a ten or even a five shot group at a game animal. It's far more important to know where your first and second shots are going to go than it is to know your average group size at a given distance. The only useful thing group size tells you is what the maximum mechanical accuracy of your rifle/load combination is so that you can then determine when you are shooting it to its potential. The rest of the error belongs to the shooter.
I would bet that there are not more than a handful of people on this entire site who can shoot a 1/2 MOA rifle to its maximum potential from field positions under field conditions. The number of them who can tell the difference between a 1/2 MOA rifle and a 1/4 MOA rifle under field conditions is likely to be even smaller than that.
From what I have seen, the primary purpose of group size is to have something to brag to your buddies about when the stars align perfectly and you shoot the best group of your life from a bench on a square range. Of course there are plenty of keyboard commandos out there who shoot better groups than you do on your best day without even leaving the house.
The bottom line here is that most people's rifles are far more accurate than the person squeezing the trigger. Once you have wrung out your rifle/scope/load combination and know what it is capable of if you do everything possible to take the human element out of the system, it is time to work on accurizing YOURSELF. With very few exceptions, even with a basic factory rifle, the least accurate part of the system is the shooter and that is the part of the system that needs the most attention.
Thats a lot of common sence...........................most of us do most of our hunting at the range, not a whole lot of field experiance. When the moment of truth comes our way our rest is never be acceptable at the range, sometimes you dont get much of a rest as you only have a few seconds to make your shot. I have had a lot of hunts that when you do spot the animal you have been waiting for you kow you only have a few seconds and he is gone........................and your right thats when lots of field experiance not group size makes all the difference..........
Buuuut all that being said in my humble opinion if a gun don't shoot we'll under controlled conditions it's gonna shoot even worst with buck fever. So why not have it shoot great groups to begain with.( But I was wrong once before )
A gun+shooter+ammo group shot under field conditions to establish your cold bore accuracy MOA is a key component with determining hit probability for a specific sized animal under varying conditions and range. Gun+ammo precision is part of this equation and only an "indicator" of gun+shooter+ammo accuracy potential.
For my purposes I strive to keep this cold "dirty" bore combo at or under .5MOA. Very difficult but completely doable.
I would agree with many of the previous comments. A .5MOA combo is tough. I hear some talk it, watch them shoot then scratch my head wondering where the heck they came up with this.
There is absolutely nothing wrong with having a .75 or 1 MOA combo as long as this piece of the pie is applied to the target size and conditions with a max range that will provide high hit probability.