The long range shooters I know use the calculated data to get them on target at the given range, and then make adjustments to their scopes as required to get it as perfect as possible. This info gets recorded into their data books as actual data and that is what is used for shooting from then on.

One thing I haven't seen mentioned yet is the repeatability and accuracy of the adjustments to your scope. The SWFA scopes are generally pretty decent, but I have seen them off more than you may think in an elevation test.

For long range shooting, take some 1 MOA grid paper and tape four of them together vertically to make one long ribbon. Hang it with a plumb bob to verify level-ness at 100 yards, and then shoot a 3-shot group near the bottom of the target. Come up 10MOA and shoot another 3-shot group. Come up another 10 and do the same (20MOA total over zero), and then a final 10 for a total of 30MOA above your zero. Measure from your zero to the center of your 10MOA up group. Measure from your zero to the center of the 20MOA group, and then the 30MOA group. Based on your given scope adjustments you will be able to calculate the real amount your scope adjusts per given click. You will likely find that a 1/4 MOA adjustment isn't exactly 1/4MOA when measured on paper.

Mine adjusts .27" per "1/4MOA" click, so I take that into consideration when trying to come up to longer ranges. Just a thought you may have overlooked. Cheaper scopes are generally less repeatable and are further away than a true 1/4MOA of 1/10MIL.