Agree with you on addressing any other "areas of inconsistency", but I'm not sure whether Crosmans are particularly prone to having velocity all over the place. Chronoed my (admittedly customized 2250B, which still runs on a single 12g CO2) on the weekend. Over 10 shots;
High: 540 fps
Low: 531 fps
Av: 536 fps
Not too shabby.