It only takes a very limited increase in pattern dia at 25yds to make a pattern totally useless at 40yds. A bbl producing true 50/55% 40 yds patterns can be generally depended upon to that distance or slightly further with good shot-size to game selections. The "So-Called" handicaps at the shorter ranges in comparsion with a true cyl bore are mostly non-existant. With the slight choke one has a much more versitile gun though, MM Notwithstanding.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra