From Spaceguy's Support_RaycastingWeapons
%ray = ContainerRayCast(%start, %end, %targets, %obj);
%start is where the ray begins
%end is vectorAdd(%start,vectorScale(%shotVec,%range)); where %start = %obj.getMuzzlePoint(0); %aimVec = %obj.getMuzzleVector(0); and %range is quite obvious
%targets is the list of typemasks the ray will react to
%obj is probably the object the raycast was fired from