There is a saying, "Old motors never die, they just CATO."
Last year I built a rocket that I named CATO-1. The purpose of the rocket was to use some Estes E16's that Curtis gave me. I also had some E12's complements of Curtis.
I gave the E12's to Tony and to the best of my knowledge, they did not CATO. Tony used them in a rocket that he designed and built that can take a lick'n and keep on tick'n.
I only had a problem with one of the two E16's and the damage to the CATO-1 was repairable.
As usually happens when I build a rocket that I say is disposable, eventually I become emotionally attached to it. So far I have flown it 8 times. Mostly on E30-4's.