I was also out wasting a box of #4 remington express today testing out the stock mod choke in a used mossy 500 I just got, and the results made me think of something that might be worth mentioning (might have been already, haven't read this entire beast of a topic). At 20 yards the pattern was fairly tight but shaped in a narrow horizontal curve (ive noticed this in other guns/chokes, and took some extra shots to make sure it was a consistent pattern). It didnt look promising because even though it was tight, it was narrow, so aim a little high or low and the shot band might miss your target. However at 25 yards, the pattern loosened up quite a bit, but, it also spread down into a nice round pattern, putting significantly more pellets in the head AND entire neck of the turkey target I was using. Simply put, its quite possible to pattern a choke and load combo at longer distances and assume it patterns good, when in fact 10 yards closer, and the pattern you were expecting doesnt exist anymore, so really, be as thorough with your patterning as you can