The Patternmaster Extended Waterfowl choke tube sure sounded like a good investment. After all, choke tubes are one of the best ways to improve your wing shooting. Pattern Master choke tubes have small 'studs' that catch the wad for a microsecond giving the shot a chance to separate from the wad. This separation is designed to allow the shot pellets to leave the cup at same time. The result is a short shot string with out a wad to blow through in the shot wad.
After testing this choke tube more thoroughly (compared to a standard full tube), I was surprised to see the results (Read the full field test report ). To its credit though, the Pattern Master did outperform the standard choke tube and I wasn't able to measure the shot string which is a major focus of the choke tube.
To put the tube in and to take it out requires a fair bit of force. In fact, I use a small screw driver and insert it into the holes of the choke tube to get leverage. The first few times I did this, I made small scratches in the metal.