Black Widows improved

I share with you some pictures of rare versions of the first US operational night fighter. Does anyone know if the equipment and weapons tested were used in combat? The collection of photos can be viewed by visiting the link below:

http://aviacaoemfloripa.blogspot.com.br/2011/02/p-61-black-widow-em-testes-especiais.html

Best Regards!

Do you honestly not know or do you ask questions you already know the answer too or could easily Google? Of course it did!