So I have seen this a lot and if this old news, forgive me. I have seen many mods allowing mechs etc at the start of the game but they always seem to forget the Guass ammo. it's actually quite easy. find your StreamingAssets\data\itemCollection\itemCollection_Ammo_all.csv Add this at line 9 or at the end whichever "Ammo_AmmunitionBox_Generic_GAUSS,AmmunitionBox,0,10" so it should look like this before you save and you will have to go to another system that has items for sale. itemCollection_Ammo_all,,, Ammo_AmmunitionBox_Generic_AC2,AmmunitionBox,0,10 Ammo_AmmunitionBox_Generic_AC5,AmmunitionBox,0,10 Ammo_AmmunitionBox_Generic_AC10,AmmunitionBox,0,10 Ammo_AmmunitionBox_Generic_AC20,AmmunitionBox,0,10 Ammo_AmmunitionBox_Generic_SRM,AmmunitionBox,0,10 Ammo_AmmunitionBox_Generic_LRM,AmmunitionBox,0,10 Ammo_AmmunitionBox_Generic_MG,AmmunitionBox,0,10 Ammo_AmmunitionBox_Generic_GAUSS,AmmunitionBox,0,10 although there should not be any spaces. This editor does not allow me to do that or I am bad at it, lol.