Make sure when you select the weapon on the stores page that you set 82H (high drag) not 82L (low drag) this allows or inhibits the drag fins but doesnt affect what the computer 'thinks' is loaded.
Second, depending if ur using the dmt or a tpod. You'll need to sensor sel down to tv to slew or press the tdc option in the tpod page to slew there.
Then use tdc commands (buttons or axis) to move it.
:)