I've always associated bursting with casings that were (a) old, and that had lost some of their resiliency, (b) weren't soaked long enough to develop the appropriate flexibility, or (c) weren't cured overnight (leaving them uncovered in the fridge to develop the casings' strength).
Come to think of it, rushing the soak or cooking sausages straight off the stuffer without a good cure first have always been guaranteed messes for me, no matter what the cooking method/temperature.
- Fillay
"Grenache is Catholic, Mourvèdre is Huguenot"
- Fabrice Langlois, Château de Beaucastel