You ask difficult questions that vexed the best minds of the time that had chance to try their thoughts with the ordnance.
Both of the bottoms could have acted as piston to eject the contents of the cannister if the top split. In French cannister this was an issue where it was less so in British Cannister. The comment upon the bottom disintegrating comes from Straith but there is no indication as when it did so. It may be reasonable that they acted in a similar manner where there was not a soldered solid bottom. The French had a solid bottom so it is likely the whole cannister was ejected. There were a number of compaints over it coming out and not breaking open. This is where we must be careful as to what we are talking about.
Roundshot had wooden sabot attached to it so this reduced the bouncing. Remember that the roundshot by definition is round and has no sharp edges whereas the cannister and the iron bottoms were. So the answer would be no, the striations would be different. The Shot contained within the cannister were not perfectly smooth and referred to as sand shot..
>Did the cannister rupture in the barrel or not? I figure the friction against the barrel might shred the cannister.
Well I have seen a film of tin cans fired from a cannon and only splattered upon hitting the ground. Not something I would like to try again.
>I doubt the heat of the explosion would have time to vapourize he tin, but would be happy to have some facts on that one way or the other.
The Boiling Point of Tin was 2270 C and you cannot get the temperature that hot. The Bronze barrel would have melted by about 1000 C. The temperature of the detonation of the gunpowder would be about 250 C.
>So let me ask a slightly different question. Ballistically or for efficacy, is it better for such a round to release the sub-munitions inside the barrel or at the muzzle?
It is better at the muzzle or after then there would be more potential energy imparted. The range of hail shot was barely 50-80m whereas cannister would be over 300m.
>What do period articles say about when the cannister walls were designed to fail, and given what we know of cannister rounds for particular guns, can we calculate if the round would be more likely to disintegrate in the barrel or at the muzzle?
Austrian cannister were designed to crumple.
The cannister would not vaporise but may soften. The gauge of the tin was thicker than a tin can.
There is no dead zone in front of a howitzer if the cannister ruptured at the muzzle which was not guarenteed. Comments upon elevation is interesting as this would influence the amount of rounds that would be in the centre of the cone.
I still have not got a good model as to the mode of action of a cannister. I think the piston driving up the container being the best model to work upon. The cylinder would give some protection to the balls striking the inside of the gun tube. Now the description of the rupture of the cannister walls is not tenable to me. It is the lid and how that acts. Tin has considerable maleability when heat so will deform. The lid is a considerable distance from the source of heat so would not be melted.