Particulars from the reports were posted in the thread on Forrest at Brice's Crossroads, so it seems you haven't read them. A summary of the inspection report cited for May 16, 1864, can be found in the O.R. The O.R. report clearly describes Forrest's arms deficit of over 3,000 firearms as well as proposals to address the issue.
While the number of arms available at any time wasn't static, it wasn't so fluid that a Confederate commander might just stumble across seven thousand boxed sets of Colt revolvers just before a battle. In all likelihood Forrest sent his men into action armed (or not) much as they had been on May 16, 1864.
I didnt mean to imply the Federal report to be a complete fabrication, only that the Ohio officer would be motivated to report the Confederate attack as carefully planned, skillfully executed and utterly overpowering, absolving him of blame for the loss of the wagons and capture of his men. For the sake of argument let's suppose his report to have been reasonably accurate.
Let's compare the two reports, the one you cited by the captured Ohio officer and the other by Confederate inspectors. The Confederate inspection included a careful review of arms, ammunition, equipment, clothing and supplies, as well as a detailed commentary on the officers and men of each command reviewed. With regard to arms, the inspector not only provided the kind and numbers available, but a general assessment on the care given to weapons issued to each command. As mentioned, the inspection included well over nine thousand officers and men under Forrest's command.
The Ohio officer's report gave the strength of Capt. Harris' command as twenty-four. He may have been given an opportunity to review the arms and ammunition of each man in the attacking party, but since he was a prisoner of war, that seems unlikely. We must also bear in mind that the Confederate inspectors did nothing other than review and report on different commands. The Ohio officer doesn't seem to have any experience in that area.
Confederate inspection reports are dated less than an month before the fighting at Brice's Crossroads. The Federal account was written several months earlier. We should also remember that the Federal report described men who had not been under Forrest's command for the better part of a year. The Confederate inspection included only officers and men then reporting to Forrest.
In summary, we have a report by an enemy officer who got a close look at twenty-four Confederate troopers not under Forrest's command. However, being a prisoner, the Federal had no real opportunity to conduct a careful review of the arms and equipment used by his captors. If he had any training or experience as an military inspector, it would come as something of a surprise to us.
In contrast, we have the compiled report of a group of Confederate inspectors having both opportunity and authority to check every weapon in each of Forrest's camps. Their reports encompassed roughly 9,200 officers and men then under Forrest's command. This wasn't the first inspection by these officers nor was it their last. The War Department in Richmond as well as departmental headquarters of Gen. S. D. Lee read, reviewed and commented on the compiled reports of these officers.
We place you on the witness stand, Mr. Upton. If asked which of these two conflicting and very different reports should be considered authoritative and reliable, what would a reasonable person conclude?