According to Union Naval reports there were 17 guns total captured at Arkansas Post.

Diagrams of Arkansas Post show that some Parrott guns were inside the fort. It is unclear what the status of those Parrott guns inside the fort was. Were they part of Hart's Battery? Or were they specifically assigned to the Fort defences? Hart's Battery was supposedly the only field battery supporting the Infantry line outside the Fort.

We know that there were 3 heavy guns at Fort Hindman (two 9 inch guns and one 7 inch). Subtract those guns of Harts battery (4 at the most) that leaves 10 guns that were reportedly captured without explaination.

Possibly two of those 10 guns could have included the two 8 inch Columbiad captured at Deval's Bluff loaded on the railcar that had been at St. Charles, But that still leaves 8 unaccounted for guns. ???????????