Today I took this rocket out to BattlePark to try it out on an AeroTech J500G. Unfortunately, upon ignition, the motor adapter thrust ring failed and the motor went up through the rocket and then went horizontally for a few hundred yards. It was one of the most dramatic launch failures I've ever seen. Fortunately, no one was injured and the damage to the rocket appears to be minor, so, it should be ready to launch again by next month. I was also lucky that one of my fellow rocketeers found my rogue motor casing. I was using a cardboard/plywood 54/38mm adapter that I had assembled with 30 minute epoxy. I had used it without problems in the past on launches with similar thrust/weight profiles. Apparently, it must have been gotten weaker over time. I had switched to this adapter when I lost my aluminum adapter (along with a rocket) a few months ago. In the future, I'm planning to switch back to an aluminum adapter.
The damage to the rocket includes two rail buttons getting ripped out as well as a minor cut/crack on one of the fins. Also, the avionics appear to have survived, but, the sleds they ride on were both damaged. The swivel I used for the booster survived, but, the 5/8 tubular nylon shock cord for the booster broke. I'm guessing having a hot motor blasting on it may have contributed to its failure.
Hopefully I'll have all of the repairs completed by next month's launch.