John,
I'm very sure that there was no arsenal at Ft Blakely... If you are ever in the Mobile.. You HAVE TO GO to Ft Blakely.. It's a confederate fort filled with trenches, redoubts, an ammunition magazine, and gun pits.. most arsenals required a water source to run a mill and machining tools.. in addition tons of wood/coal to run a furnace for casting metal, horses, wagons, roads to bring in material such as processed copper and iron.. and people to run the arsenal.. I think most of the confederate's ammunition came from Selma.. If you every have a chance to look at the shipment of artillery pieces from Selma to other parts of the confederacy, you can see that most pieces went to fortifications at Mobile. As I'm sure the same goes with ammunition. To address your pic of Brooke sabots.. My friend dug 6 US 100lb parrott shells in one hole in the bluffs at Vicksburg.. the shell were located behind confederate line and had been fired.. all the fuses had been screwed out and i believe the powder was removed by the confederates.. Either to make the shell inert or to utilize the powder. Maybe powder was a commodity???. Copper was a huge commodity.. especially when copper suppliers in the south were captured by the north.. if is a war time pic i think that they were trying to salvage the cooper.. 10lbs of copper sabot.. that's a good amount.. But who know? Jaime