A beautiful flight on a Cesaroni 38mm I216 Classic White "Longburn" motor with a 3-second burn time. 314mph on the way up, and probably 65mph+ into the ground. [Insert sad face.] It was immediately apparent what the cause of the failure was: One of the three shear pins holding the nose cone to the top body tube failed to shear -- it was sticking out of the nose cone shoulder and bent 45° down by the body tube separation. This significantly reduced the force of the nose cone separation (2.5G of BP), which in turn failed to pull the main parachute all the way out. The parachute was hanging halfway out of the top of the tube still neatly folded and taunting me when I retrieved the rocket. Top section is 100% reusable. Bottom section took heavy damage: one fin had its epoxy fillet separate from the fin (but not from the cardboard body tube, which is very surprising) when it hit the ground, and equivalent body tube damage on the opposite side where it pushed over. Electronics bay was completely destroyed, along with some of the contents inside (arming switch mount, altimeter sled separated from the metal tubes it slides down on, and both 9V battery holders broke off), but the Raven2 altimeter ($160 by itself) made it through unscathed and provided telemetry from the flight. I should have added a second back-up charge just in case.... this was the first time I /didn't/ do that with a Raven2 flight. Someone kick me.