I've mentioned the concept of "practical accuracy" a couple of times and I've gotten a few questions about what exactly I'm talking about. So, I'll explain in brief.
Intrinsic accuracy is the mechanical accuracy the rifle is capable of with a given load. Generally measured in the size of the group in inches at 100 yards or in the measurement of minute of angle. This is the accuracy test you typically see in magazines or television programs or on the Internet. One thing is the same in all cases however- the equipment used is meant to remove any influence the shooter may have. Typically, this is a solid bench rest and a Ransom Rest or 50 pounds of sandbags all placed in such a manner to eliminate any error the shooter might induce into the result. The skill of the shooter is nearly irrelevant if he doesn't manage to yank the trigger hard enough to pull the rest over. This is NOT what I'm talking about when I use the phrase "Practical Accuracy".
Practical accuracy is the same measurement in inches or minutes of angle with a couple of differences. The shooter does not use a bench rest or sandbags and time factors into the equation- the shots are fired from a field position under time pressure. In other words, the measure of intrinsic accuracy is that of a rifle isolated from it's firer whereas practical accuracy incorporates the firer and the rigors of field shooting into the measure. These two numbers will not be the same although a highly skilled master can get pretty close under ideal conditions- but they are not the norm. If your practical accuracy gets to 200% of your intrinsic accuracy then my hat is off to you and you'll be a deadly marksman indeed- far above the ability of your peers. The prone position will yield the best result and offhand typically the worst which is why my effective range is three or four times farther prone than offhand. Your results will likely mirror that as well.
Why does it matter? Well, in my hunting ground there is a notable absence of bench rests and sandbags and I'd wager yours doesn't have them either. You really have to know what you and your rifle are capable of as a system, not just the rifle itself in some abstract construct at the range. I've coached a number of hunters with marvelously sub MOA accurate rifles from a bench that literally had trouble hitting the vitals on a deer at 100 long paces. Their rifle was up to the task but the hunter wasn't.
It would certainly behoove the hunter to get out and practice from field positions- offhand, sitting and prone- to see a realistic picture of what they're actually capable of in the hunting ground. I'll refer the reader to my posts "Practice Makes Perfect" Parts 1 and 2 for more information. Testing a new load or zeroing a new scope from the bench is a great idea and we should test the intrinsic accuracy of our pieces from time to time administratively as barrels do burn out, scopes fail to hold zero, bedding shifts and so on. But don't confuse yourself- it does little to prepare you to fire at game animals and says little of your skill as a shooter.