I took an intermediate pistol class over the week end at my club ($250, 14 hours, 500 rounds fired, one to one student to instructor ratio). I had a great time and learned a lot. One of the instructors (22 year retired LEO) had these plastic cartridges--not snap caps--for use in training for type I/II/III malfunctions. They were color coded for the different calibers. During live fire drills they were also mixed into the magazines by the instructor with live cartridges forcing the student to fire, correct malfunction, continue firing--excellent drill. I've been looking for these on the web--anybody seen them?