According to Brister, the most significant variable in shot string length is _not_ deformed pellets...these are considered "lost" from the pattern at any significant range, and play very little to no role in breaking targets. His work concluded that initial air resistance is the most significant variable...the more pellets that can be at least partially shielded from maximum air resistance for the longest time, the shorter the string will be. Hence, his empirical data showing that at target breaking distances, Full choke has the shortest strings. The group of pellets is "packed" together like billiard balls in a triangle as it comes through the choke, and this tightly-clustered group shields more pellets from the full brunt of air resistance, for a longer time.
Some simple arithmetic will demonstrate that shot string has no role in either breaking or missing a target. A 10' shot string will pass a target before the target can travel more than a couple of inches. Target speed at 30 yards is about 35 MPH. This can quickly be changed to ft/sec (5280 X 35 /12 X 3600). If the shot has slowed to 1000 ft/sec and the string is 10 feet, things get very simple. Remember, the target is not going at a right angle to the shooter.
Without a shot string, I would think the breaks would be entirely different. Not saying more or less, just different. From the pictures previously posted here, with a shot string, the leading pellets break the target and the trailing pellets hit the dispersed target pieces creating quite a smoke ball in some cases. Trap wouldn't be quite as spectacular without a shot string.
Well shot string might not get any targets but on a hard left,I get a chip on the left edge,,,,,,I have to think I hit it with the tail end of my shot string...
Years ago there was a fellow that measured shot string with a station wagon and a boat trailer with about 16 feet of cardboard affixed. I think it was,40yds,40mph,and to get all the shot on the cardboard,the lead was the back of the car.(too risky for my blood) So I guess,you can miss a little in front but not a bit behind,yes..
About a year and a half ago I sent to some folks a little program that showed perceived and actual lead. Seems that a 35mph target with shot going 1000 feet per second,a 90 degree target and a 35 degree target have the same actual lead,but not perceived lead. Whiz and Devi were two that I sent it to.
A full cohoke will have a shorter shot string than modified from the little that I know. The old belief seemed to be the opposite. The original barrel guru Tom Seitz was the first that convienced me of this theory. He did tests to prove such. I have no idea where the data is now.