This is something you mostly see in old, 1930s cartoons (though it did put in a modern reappearance in Star Wars): an anti-aircraft gun with a pair(s) of barrels, each having a trumpet-shaped end, that “pump” out the shells in an alternating rhythm. (That is, as one barrel fires it retracts in recoil; then the other one fires while the first one returns. The shots appear to be spit out of the gun like so many pumpkin seeds.)
Now, I think I’ve seen these in real life (I mean, in real documentary footage). They were British, and of pre-WWII vintage, IIRC. Am I right or am I imagining this?
If they did exist, what was the purpose of the blunderbus-style ends, and the crazy rockin’ rhythm?
They were certainly real. I believe that the movement you describe is how the gun absorbs recoil and the cones on the end are flash hiders (helps keep the muzzle flash from ruining the night vision of the gunners).
The movement of the barrel is not just to absorb recoil but is how many automatic weapons function. The entire barrel, breech and bolt assembly move backwards as a single unit. This short delay gives time for chamber pressure to drop to a safe level for the bolt to open. After a short travel breech and barrel stops while the bolt keeps moving, unlocks and extracts the spent casing. Some locked breech weapons have a fixed barrel but they usually require a gas port in the barrel near the muzzle in order to provide the delay and operate the action.
On a side note I was looking at the “lock, stock and barrel” exhibit in the DeWitt Wallace museum in Colonial Wiliamsburg. I had always wondered why a blunderbuss had a flared muzzle and according to the placards it was merely so it would look more intimidating. Wikipedia says it’s to facilitate loading so take your pick.
I don’t think we find them scary since we’ve been conditioned by years of Tex Avery cartoons. I’m sure someone facing a blunderbuss 400 years ago would find it somewhat less comic. The Williamsburg exhibit mentioned that it didn’t spread shot patterns any better than a normal barrel but I’d like to see a controlled test. A choke restriction of a few thousandths of an inch can make an enourmous difference in the the spread of the shot pattern. Ease of loading? One thing you would not want to do is drop random chunks of rocks and shrapnel down a funnel shaped barrel. I think it would be likely to jam up as the bore narrowed and likely cause a blowup.
I have read in several sources that the blunderbuss barrel shape in question was neither for loading, nor shot spreading, nor intimidation. Instead, it was simply a stylistic touch that mimicked the shape of contemporary cannon barrels. These same sources had pictures of what they called “cannon barreled” pistols and long guns for comparison.
I agree with that assessment. The couple blunderbusses that I’ve examined first-hand exhibited the flaring only on the outside of the barrel. The actual bore was a plain cylinder.