The Winchester 1911 SL. This is the shotgun Winchester designed to get around Browning's patents on the Auto-5. One of those patents was for the tab on the Auto-5 bolt. So how do you cycle the action to unload the shotgun if you can't work the bolt?
You rack the bolt back by pushing down on the barrel, repeating this action until the magazine is empty. Ergonomically, you can see that unless you were very aware of your positioning, it would be possible to be in front of the muzzle as you pumped the barrel. The inevitable result of this lead to the gun being nicknamed the Widow Maker.
Here's a blog post with more information, detailed pictures, and the author's impressions shooting one of these old guns.