1st (Burnet's) Battn, Sharp Shooter's "A thru I" listing is found in National Archives Microform M323 Roll 260 which is in the listing of

Roll 258, headed "1st State Troops, 1st State Troops, Infantry, 6 month, 1863-64, A - G,

Roll 259 H - S,

Roll 260 T - Z,
1st (Burnett's) Battalion, Sharp Shooters, A - H

Roll 261 I - Y

.....

Footnote lists in First State Troops, Infantry (Six Months, 1863-1864: First . . . . [hidden]
(Burnett's) Battalion, Sharp Shooters

Confusing? Yes.

I have found that to ID hidden units in Footnote, one needs a copy of :

"Military Service Records, A Select Catalog of National Archives Microfilm Publications," National Archives Trust Fund Board, National Archives and Service Administration, Washington, DC, my copy is dated 1985

I cannot fathom how Footnote put things together and they are not consistent in format. Not a problem, just a comment. Sure is a lifesaver.