I've tried setting the guns up with manually editing my .ini file and using the config tool for UI
They both work as player one. (see ini info below)
My light gun ID's are joy5 and joy6
; Light guns (Lost World)
InputGunLeft = "KEY_LEFT" ; digital, move gun left
InputGunRight = "KEY_RIGHT" ; digital, move gun right
InputGunUp = "KEY_UP" ; digital, move gun up
InputGunDown = "KEY_DOWN" ; digital, move gun down
InputGunX = "MOUSE_XAXIS,JOY5_XAXIS" ; analog, full X axis
InputGunY = "MOUSE_YAXIS,JOY5_YAXIS" ; analog, full Y axis
InputTrigger = "KEY_A,JOY5_BUTTON1,MOUSE_LEFT_BUTTON"
InputOffscreen = "KEY_S,JOY5_BUTTON2,MOUSE_RIGHT_BUTTON" ; point off-screen
InputAutoTrigger = 0 ; automatic reload when off-screen
InputGunLeft2 = "KEY_LEFT" ; digital, move gun left
InputGunRight2 = "KEY_RIGHT" ; digital, move gun right
InputGunUp2 = "KEY_UP" ; digital, move gun up
InputGunDown2 = "KEY_DOWN" ; digital, move gun down
InputGunX2 = "MOUSE_XAXIS,JOY6_XAXIS" ; analog, full X axis
InputGunY2 = "MOUSE_YAXIS,JOY6_YAXIS" ; analog, full Y axis
InputTrigger2 = "KEY_A,JOY6_BUTTON1,MOUSE_LEFT_BUTTON"
InputOffscreen2 = "KEY_S,JOY6_BUTTON2,MOUSE_RIGHT_BUTTON" ; point off-screen
InputAutoTrigger2 = 0 ; automatic reload when off-screen