Allchin Gun Parts came through, his moonclips fit perfectly on the Super Comp brass. Nice snug fit, no fighting getting brass in or out. The center bore is also the same size as the mandrel on my TK loader.
A friend has a BMT mooner for him 929 and I'm going to see how it works with Super Comp, 9mm is so close I don't expect any problems. BMT offers one for standard 38 Super but said they hadn't ever experimented with the 38 Super Comp brass to know for sure if it would work, they also thought the 9mm for the 929 should work