None of these charts seem to indicate anything other than percentage or overall spread. "All" patterns will be more dence in the center than on the edges & ordinarily more so as the chioke increases. A pattern with high core density will not degenerate as quickly with rang increases as will a more uniform patter, but these charts do not reflect this.
""IF"" patterns had a linear spread & totally uniform distribution it would be a very simple mathematical equation to figure the density at any range desired. if that were the case, double the range, with same choke it would take 4 times the "Number" of shot to maintain the same density plus you would have to go up in shot size to maintain energy so the load weight would increase even more.
On the other end of the spectrum, pattern density is decreased much earlier with "Spreader" loads. It's my understanding that they don't widen the pattern, but spread the shot out within the pattern much earlier.
