This is a good question. Loading and shooting multiple rounds in rapid succession appears to increase the likelihood of a cook-off substantially. I would be interested in hearing from those who have witnessed “cook-offs”…. After about how many rounds are these most likely to occur?Does there seem to be a number of reloads after which this is more likely?
How likely is it on the second or third reload?
Another thing I have wondered about is whether the type of breech has anything to do with it. Original American percussion military muskets and rifles, as far as I know, had a bolster on the side of the barrel for the nipple, with a very simple breech plug. The flash channel from the nipple base goes directly to the main charge, and the face of the breechplug is flat. A lot of the reproductions use a patent breech, in which the breech plug and bolster or nipple seat are one unit, with a smaller-diameter powder well or chamber connecting the bore to the flash channel. Is one more likely than the other to “cook off”?
I completed “cannon school” at Castillo de San Marcos in St. Augustine maybe 10-12 years ago. I recall they stressed the importance of waiting a certain amount of time in between shots with the cannon to allow any possible ember time to burn out. Maybe half an hour? I don’t remember. I do know that you do not want a cook-off while loading a cannon.
Notchy Bob