[USMC0861]

What I know about Army MOS codes could fit on the head of a pin. But Cannon Fire Direction Specialist sounds like what the Marines call Fire Direction Control Man. They work in the Fire Direction Control (FDC) and plot and figure target data from the FO's , TOT's, Register Targets, and maintain other data.

They also have cool nick names given to them by the Cannoneers and FO's. Some of these include but are not limited to

Fresh Donuts and Coffee
Fritos, Dorritos, and Cheetos
Fresh Dry Cammies
Charts and Darts
F*cked up, Dumb and Confused

As far as the other MOS's in Arty are concerned FDC is the root of all evil in the Arty world. They are way you fire 6 round adjustment missions and still have 2 rounds out of sheaf on the FFE. They are the reason cannon cockers get woken an hour after hitting the rack...because the round count board in FDC is screwed so someone has to count projos and fuses.

Have a blast.