.....patterning .....for upland hunting?
My approach to patterning depends on my goal.
That might be to determine point of impact if I'm doing stockwork (I'll shoot at a bullseye 16 yds from my eye) or to determine the true choke of combinations of shells and chokes ( I'll count the pellets in a load, shoot at 40 yds, draw 20 and 30" circles around the center core, count strikes, figure percentages, etc.). I haven't done the latter in years but, if I did, I'd probably have some interest in computer analysis.
For the OP's task, I prefer to shoot at life size silhouettes of the gamebird at the average distance I expect to take my first shot and then the more extreme distance I might try for a second shot. For grouse and woodcock, for instance, that would be 18 yds with the first barrel and 30 yds with the second. I'm not interested in 30" circles and percentages...the effective pattern diameter is what it is, depending on target size, payload, choke and distance.
My 20ga, with the 1 ounce of #7.5's I prefer, is choked .005 and .015...
Not overly scientific, but my results were entirely satisfactory for the couple of decades I hunted them...few cripples and rarely a mangled bird.
