pf, constriction tells the story. If the work is done in a craftsman like manner, there is little to be learned from a single pattern. To actually know, with modest precision, how your choke is really performing you need ten patterns and statistical analysis. Performance of patterns from same load and gun vary enough that single patterns are not a reliable predictor. The reason there is so much misinformation about chokes is that most data has been taken with very insufficient patterns. This is pretty much due to the difficulty in analysis. There is a program called Shotgun Insights that will read digital photos of patterns and perform the needed analysis. I recommend you go with a known smith and known constrictions or prepare to do some serious research with a whole bunch of patterns.
DDA
