Originally Posted by
Tim Allen
What you are doing is taking a snapshot of a random shot pattern but it is a 2 dimensional solution to a 3 dimensional problem. A pattern does not arrive flat but is elongated with pellets arriving first then last (obviously). If you fired five shots (at separate sheets) you're unlikely to get the same pattern. (shooting four shots at one sheet doesn't tell you much other than you were consistent with your deliberate point of aim)
For my mind a point of impact test is far more critical to good shooting with a shotgun as it is mostly about gun fit and impulse (as well as self control and shooting within your ability). To do your pattern test you deliberately aim (rifle) at the pattern sheet. An action that will see mostly misses on moving game.....
When I look at your sheets I think you have got your choke selection spot on from 35 yards and closer with around 20 odd effective pellets, though you maybe shooting slightly left. That same choke looks ok at 40 yards but will let you down occasionally at this range and beyond with around 9 effective pellets. Something also worth considering is that at 40 yards your pellets are doing a great job at punching through paper but will be loosing energy and penetrative power for game. If you feel you are a good enough shot to shoot regularly at 40 yards you might like to test the next choke down?
You can read too much into patterns. I pretty much leave my quarter choke in and rely on my ability select a target I know I can kill by putting the shot and target on a collision coarse. That 35 gram load of 4's you've tested has proved very effective on everything up to Canada's when shot in such a way.