Loading Deck gun?

Originally Posted by USS Rustbucket

I'm in my maiden patrol of my newbie career. I have GWX gold installed.

I have cripped a Medium Merchant I want to finish off with the deck gun. Problem is the deck gun isn't loaded. How do I load the deck gun? Or did I not arm the boat with shell prior to leaving port?

Man the deck gun yourself and choose what type of shells to use with a mouse pointer. That should start things moving.