Originally posted by Ed Kolis: There are settings for firing arcs in both SpaceObjects_XFiles.txt and Main_PurchaseShipsPlayer.txt; do your settings in both of those match?
correction:
arcs are defined in SpaceObjects and ComponentConfigurationSlot(player/enemy) files
As of the current patch, the spaceobject_xfile definitions override the definitions in the slotconfiguration file.
Easiest way is to copy one of the xfile entries and give it a new roman numeral in the name or a revision letter or somesuch. Change the arcs there, and have you purchaseship use that new xfile hull plan.