Most likely all that has been done is the chokes have been opened up. Perhaps shot to see what the pattern looks like if you requested it for a specific load and to make sure they are close to where expected.
I often chuckle aloud when I hear some shooter claim his misses are the result of a gun not shooting to his point of aim because the pattern was 2" high or 4" off at 30 or 40 yards. Take a 2 X 4 and stand it at 30 yards with either edgewise or large side facing you. Then take a 30" circle of cardboard and nail it to the 2 X 4 and see the relationship of your pattern to the 2" or 4" point of impact error. Perhaps 6" or more at 40 yards is a problem but not a couple inches.
Real problem many shooters have is estimating distances and perhaps too tightly choked bores. If your gun is too tightly choked your pattern will be smaller than expected. If you can not estimate distance correctly your leads will never be correct. A 30" pattern gives you what in reality is a plus or minus 12-15", call it one foot margin of error, for centering the bird or target, because the edges of any pattern tend to be very thin.
Do the math. If a crossing bird travels say ten feet at thirty yards while the shot travels 30 yards and is centered in your pattern, if it travels more than eleven feet at 40 yards, which it will, you will miss if you do not know the difference in distance between 30 and 40 yards and change your lead. Some will point out the pattern spreads more in distance but it is a cone shape not a cylinder so a 30" pattern at 30 will be larger and more full of gaps at 40 yards or tighter and smaller at 30 yards if 30" at 40 yards. Get the distance right to get the lead right or every shot is largely luck.
I did the calculations for Teal once and figured I needed to be within 2 yards plus or minus to hit them with consistency at 30 to 40 yards. Since they are still in great numbers I never master the distance estimation in their case but I still love shooting them.
Now if you really want to get it right you need to figure angles into our equations, as well as distance, but I left my pocket protractor at home. On a 90° crossing bird the lead is more than at 45° or at 30°. We will leave deflection, raising birds, speed changes, and falling birds for another day.
