RE: minimum accuracy requirements
I don' t think that everyone is on the same page here. Are we talking about ACCURACY or MARKSMANSHIP?
Some people, including the original poster I think, are talking about ACCURACY. Accuracy is that ability of the rifle and ammo to be consistant both in group size and placement, without taking the shooter' s skill into consideration. If you really want to see how accurate a rifle is then you should clamp it into a shooting vise or similar that takes the human factor out of the equation. So a perfectly ACCURATE rifle is on that will shoot every bullet through exactly the same hole as the last, every single time. Of course, such a rifle is a mythical beast, but the closer to this level of perfection, the more accurate the rifle is.
Then there are some who are talking about marksmanship. Marksmanship is the ability of the shoot to " to his part" to put the bullet where he wants it under real shooting situations. Marksmanship involves the human element, such as the ability to dope the wind and range, zero the rifle for the given range, and apply proper shooting form and techniques to make it all happen. When one talks about getting every shot into an 8" paper plate at X range they are referring to a combination of both accuracy and marksmanship, or what I like to think of as " practical accuracy."
An inaccurate rifle (one that shoots a big or erratic group), even in the hands of the worlds best marksman, is still likely to miss. The same is true for a very accurate rifle in the hands of a poor marksman. The trick is to get a rifle and load that is accurate so that you can refine your marksmanship skills knowing that misses are your fault, and not the gun' s. For accuracy purposes, I like to keep my groups under 2 MOA with my muzzleloaders from the bench (we don' t get to hunt deer with CF rifles in Iowa). At the ranges deer are shot in Iowa timber, where 100 yards is an unusually long shot, 2 MOA of accuracy is sufficient. After I establish that my chosen load is accurate enough, then I will shoot at an 8" target from real world shooting positions and see if my marksmanship is up to the task. If I can keep every shot in the 8" circle out to a given range, then I' m confident that my practical accuracy is good enough for the field within the established range limits.
Basically, the more accurate the rifle is, then the less critical the marksmanship is and the bigger the shooters margin of error is. A less accurate rifle will mean that the marksman' s ability and margin for error will be smaller.
Mike