He creates more questions than answers....

"For the hunter using a 100-150 yard hunting rifle, such as rifles chambered for what are fundamentally pistol cartridges (.357 Magnum, .44-40, .44 Magnum, etc.) or low pressure cartridges like the .38-55 and .45-70, a 4 MOA group will suffice. 4" groups at 100 yards don't look very impressive at the range, but 4 MOA groups mean all bullets within a 6" circle at 150 yards, about the maximum useful range of this class of cartridges. A .44 Magnum rifle that will put all of its bullets into a 4" circle at 100 yards is a deadly deer rifle, as accurate as it needs to be."

If you take into what he listed as factors....

"At 400 yards the merest twitch by the hunter, or a puff of wind 200 yards away, will throw the bullet clear out of the kill area. The inherent accuracy of the rifle has become a secondary consideration compared to other variables."

Let's not forget the spin of the bullet changing impact point on longer shots or that the animal can move at the same time you break the shot, that a percentage on those shots could miss the 6" kill zone. His article doesn't state practice more, or use the right components to get the best accuracy, it states being mediocre is fine.