[Jim McDougall]

Philip, in answer to your question on Mexican powder and arms logistics in the Alamo period, during my research on that fell short as no specific mention of the source of their powder was found.
I can only presume that the British, who supplied most of their arms also provided black powder as well.
The main issue in the powder that remained in the Alamo among numbers of captured arms and cannon, was (as described by Mrs Dickson in her account) 'damaged'.
It was March in Texas, known for damp, cold conditions, and it is not hard to imagine the powder becoming unreactive or insufficient for normal use.

The Mexican army rifles were notably insufficient in firing, and extra charge as well as buck and ball were used to compensate. While the Mexican army was said to have steadily bombarded the Alamo for over a week before the attack, it was noted that none of the fire had caused notable damage or casualties. The powder charges were apparently inadequate to effectively reach their target.

I agree that the Jiavana cannon was probably an intimidating element, despite the fact that its maneuvering was not particularly expeditious.
Its rather like, if they've got that huge thing up there, who knows how many other pieces are about.
Your notes on moving huge siege guns through horrible transporting conditions remind me of the movie "The Pride and the Passion" with the troops struggling with ropes and oxen etc. trying to move one through muck and mire.

These insights into the artillery aspects of warfare are fascinating, and provide great overall context and dimension in understanding the logistics of these weapons and battles.

Fernando, looking back at the chart of guns in the Portuguese report, it is fascinating to see the different terminology used in the variant types. I had not been aware of differences between a bombard and other guns, nor what a howitzer was exactly.

These discussions make me appreciate more the profound contributions our late friend Matchlock made here, and wish I had paid more attention then.