If you are an enemy fighter, you would want to be very careful about trying to sneak up behind the Catalina flying boat. Sticking out the back is a {Sound effect of needle dragging across a vinyl record...}

In the original description I typed "50 calibre surprise just waiting for you". Because I looked at that and thought "Yeah, that would have to be a .50 cal". Had I seen it more side on I probably would have known better.

In updating these comments in 2024 I actually did some background research. The Catalina did in truth pack a couple of .50 cal weapons, but they were in the waist "blisters" that will be visible in image 30306. According to every reference I've consulted, including documents from the US Naval Institute, the guns carried in the nose and the ventral slot were .30 cal. And indeed, since a flying boat under attack would more likely head for the clouds or, if there were none, for the water where it could land and its aggressor could crash, the ventral gun probably wasn't that important so there's no point wasting extra weight on it.

Also... that does bear more than a passing similarity to ye olde M1919 Browning. I'm not saying that it is, but the overall appearance is not a million miles away.

My bad...

Addendum: My personal opinion is that Facebook is a sociopathic organisation that steals other peoples' intellectual property (including the images in this gallery) despite being explicitly denied permission to do so.