I did a extensive amount of pattern testing with a briley tnt spreader choke a few years back through a crio plus, ber/ben mobil and inv plus threads. While it does as advertised, somewhat. I found little benefit from shot sizes bigger than #4's because of lack of pellet count and to much thinning of annular ring. Which was the original idea behind buying it. It worked well with most factory steel loads in # 4,5,6's and worked very well for my son with hevi #7's @ close range and for me with hevisteel #6's.
"Can't never did anything! So don't listen to them... They wouldn't know good owl manure if they were standing in it!"
Arthur J. VerStraete (1920-2009)