swatkat
Down these mean skies, a kat must fly!
Just had my second CATO of a 40-120 Hobbyline case (my only CATOs in ~50 composite reload flights in 18-38mm). In both cases, the forward closure blew out due to apparent thread failure (post CATO, the threads on the forward closure are notably shiny, i.e. they have been scraped off to at least past the depth of the anodizing). Motors blew out just after coming to pressure, still on the rail. The rear closure and nozzle held, actually blowing out the back of the rocket and taking the Estes plastic retainer with it.
Sadly, both cases were outside the warranty so I'm kind of hosed on that end. Anybody else had similar failures with this casing? Seems like the thin wall (and thus shallow threading) of the case might be a marginal design (if anything, you'd think the plastic nozzle would go first in a true overpressure)? Which would be a shame, because I love the reloads - not a huge variety but inexpensive and great for the Estes PSII line.
There was a recall on the Hobby line 29/40-120 for the forward closure threads. There was a batch where they were tapped too deeply and the case itself would fail under pressure right at the machined screw in portion for the forward closure.