Thanks for reminding me. This is where I got the reference that the 1st Indiana's guns had remained at Pine Bluff as part of Battery "H" 2nd U.S. Colored Artillery there. But I had forgotten the mentioning of being 4 guns again.

Evidently the gun captured in Mississippi had been recaptured sometime in 1864 and returned to the 1st Indiana by at least December of that year. Hence 4 guns in October 1862, 3 guns in October 1863 at the Battle of Pine Bluff, and then again 4 guns in December 1864, when the 1st Indiana Cavalry was being reorganized as a Veterans regiments and most of the men mustering out.

But what gun used a 7 pd shell, was small, made of steel, was rifled, was light enough to keep up with fast moving cavalry raids, and could have looked like a "Mountain Rifle", or a "small 6 pounder"? These could certainly be discriptions of a 2.9" Blakely gun. But the Blakely wasn't an unknown gun to either side. And certainly the Commander of the battery and Regiment, such as Major Baker and Col Pace, should have know what they were if they were Blakely's