It's an interesting topic with regard to equipment. Custom gunsmiths draw distinctions between mechanical accuracy and practical accuracy. Some things you might do to a gun, bedding, barrel tuning and whatnot, are geared toward mechanical accuracy. The sights, trigger, stock fit, etcetera, are geared toward practical accuracy. Practical accuracy is defined as anything that improves the shooter's ability to make use of whatever mechanical accuracy a gun may have. Trade-offs needed to achieve practical accuracy are easily short-changed in emphasizing mechanical accuracy, especially as regards gun weight and scope magnification. In the field, only varmint hunters commonly have platforms that can make practical use of what amount to being heavy target rifles.
The idea of segregating what which tests the rifle from that which tests the man did not originate with Jeff Cooper. He was expanding on it to include more shooting positions. The idea first formally appeared in Germany and Switzerland in the form of schuetzen (or schützen) rifle matches. Schuetzen rifles were the top accuracy guns of their day, and continued to be so into the first part of the last century. The early schuetzen matches (18th century) are reported by some to have been offhand-only, but by the second half of the 19th century, with the development of single-shot cartridge actions, these matches had evolved to commonly have two stages: off the bench and standing offhand. The idea behind those two stages was always specified as being to prove the gun and the man, respectively.
Cooper also questioned Whelen's comment that only accurate rifles were interesting. He felt the "handiness" of lighter weight and short barrels and other practical features could at times outweigh mechanical accuracy in the field. He admired Jim West's Co-pilot (guide gun) concept. Definitely a short range emergency stopper first and an accuracy gun second. Very useful to the PH having to stop a charging beast a novice client had got too excited to hit. With ghost rings it is a terrifically quick and effective deer and bear gun in woodlands. Cooper was irritated that Marlin had, as he viewed it, stolen that concept and produced an inferior embodiment of it, giving no credit or acknowledgment to West for developing and popularizing it.
Cooper's doctrine teaches sighting a high power rifle two inches high at 100 yards (to have roughly a 200 yard zero) as the best method for the field. Most common chamberings are then around two inches low somewhere in the vicinity of 230 yards. He did not distinguish between optical and open sights in this practice, even though the higher sight line of a scope results in elevating trajectory more at point blank range. He had us sight any high power rifle this way, regardless of how "flat shooting" it's chambering was supposed to be. He thought it made sense to give up two inches of vertical precision either side of the point of aim, since it didn't detract from lethality on man-weight targets and larger, and it allowed one to dismiss any thought of adjusting sights or holding over or under for heart and lung shots to 230 yards; a range within which most game was taken.
Cooper observed that, with training and practice, a shooter could usually find a field position that would let him hold a four inch circle at any range out to 300 yards, and a highly-trained shot could do it to 400 yards (where slinged-up prone or a mechanical support would be needed). You then only need a 1 3/4 moa gun and wind conditions to stay in an 8" circle at 400 yards, but at the shorter ranges more common in the eastern side of our country, you obviously do not. Also obvious is the precision of the gun and shooter can be reversed. Where my friends and I hike the Catskills, in New York, I've only once seen a potential clear shot at deer far enough out that a slug gun wasn't suitable. I say potential, because, of course, it occurred out of season, as, seems to me, is the case with 95+% of the best potential shots I see.
Having said all that, I thought it might be of interest to present a different view based on shooting out west over greater distances. Probably the most stringent hunting accuracy recommendation I've seen published is Harold Vaughn's. The following is excerpted from his book, Rifle Accuracy Facts. In the book's two opening paragraphs in the 2000 edition, he writes:
"Some forty-five years ago, when I started big game hunting, I became dissatisfied with the accuracy of commercial rifles. You just don't want to miss after spending days and sometimes weeks looking for a big trophy, and then finally getting one shot at three hundred yards or more. Most sporting rifles are not accurate enough for these long range shots. The commercial rifles that I tested would shoot 5 shot groups ranging from 4 inches to 12 inches at 300 yards, and that just isn't good enough for a serious trophy hunter.
"Now, a lot of you will say that your rifle is capable of shooting more accurately than you are capable of shooting. Now I'll buy that, if you happen to be one of those people that just can't shoot because of flinching, or not being able to see well, or for some other reason. However, I can't agree with this for the majority of shooters, because I have fired thousands of rounds through accurate sporters on machine rests where the only skill involved is putting the cross hairs of a 20 power scope on the center of the target. Invariably, I get about the same accuracy when I, and other folks, shoot the same gun from the shoulder at prone position or from a bench rest. Bench rest shooters have been consistently shooting better than 0.3 inch 10 shot groups at 100 yards for years with specially made heavy rifles and carefully assembled ammunition, while it is rare for a sporter to shoot better than 1.5 inch 5 shot groups at 100 yards. This should be ample proof that most people can shoot a lot better than their guns are capable of shooting. By the early 1960's I had lightweight sporters that would reliably shoot 2.5 inch groups at 300 yards, which is adequate for any big game hunting. This was done by replacing the barrel with a custom barrel chambered with my homemade reamers and by replacing the stock with a carefully inletted stock."
What I like about that is the conciseness of his accuracy requirement, even if it is only advantageous for those shooting at longer ranges than most of us usually see. It also serves as a reminder that even if we don’t truly
need great accuracy most days, there is no penalty for having it, and that it will give us better feedback about our shooting technique when practicing on targets. Many times at the target range I have seen people who were sure their guns outshot them, subsequently dumbfounded when a borrowed match accurized rifle, otherwise identical to their own, improved their score 10 points or more.