Warren Johnson created the SPRED patterning software in the 1990s. As Warren writes, “I developed SPRED to provide quantitative, scientific answers to important questions people have had for decades about the relationships between shot patterns and breaking of targets.” From the original release, it has received accolades as one of the all-time great desktop tools for those with an interest in pattern effectiveness. I've been using Warren's Choke Chooser for decades, but it has been very hard to find for many years.

Now, at long last, you can get your own from Roland Leong of Shotgun Report, while quantities last, and you'll be glad you did. Very, very, very highly recommended!

https://www.ebay.com/itm/154140302262?hash=item23e37a5bb6:g:wf4AAOSwETtegmjm