Many of the men manning the guns of Brown's Battery were seconded from the 27th(Shaler's) Arkansas Infantry in August 1862. I have cross checked the records of these men in CSR and found that 20 of them (out of 27) contain the same card i.e.

Pvt. att. Brown's Btry of F.A.
Subject: rep. Co.* Shaler's Rgt.
Title of Record: S.O.#23 Dist. of Ark. Holmes
Date: Apr. 11 1863

I cannot trace a copy of Holmes' order, but would surmise that it is the order ordering these men to report back to their former command. This may imply a disbanding of the battery about this time. Although the battery was still shown in the OR as being part of Colton Greene's Brigade in May 1863, it was indicated as having been ordered to Little Rock. It may be that this was under instruction via S.O. 23.

If anyone has access to a copy of S.O. 23 this may explain what happended to the battery!