Comments
Very near the end of the burn, the aft closure completely blew out. Some unburned propellant remains in the aft grain, all other grains fully burned. No evidence of burn-through on the casing and the threads are still in good condition. There was a small ~1mm chip of damage on the end of the casing (somewhat visible in photo), but it looks more like a tear than burn through, and there was no corresponding damage to the casing.
