James Rummel has pictures and descriptions of five handguns that were very innovative designs, but turned out to be useless in real life. These include the Henrion, Dassy & Heuschen twenty-shot revolver, manufactured in France between 1921 and 1928.
http://www.hellinahandbasket.net/2009/07/5-brilliant-innovative-handgun.htm
"Another shot at the French military history"
Actually, only three of the five handguns featured are French in origin. The other two are, respectively, Austrian and American.
Also, only one of the guns was ever intended to be a military arm. That is the one that was designed by an American, the LeMat pistol. All of the others were designed for, marketed, and sold to civilians for personal self defense.
It is true that I crack wise about how the French tend to come up with odd pistol designs at the end of the essay, but that is simply because I suddenly realized that the majority of the examples I used came from that country while I was writing the Epilogue. My apologies if I caused any offense.
Just like anything else, more doesn't necessarily mean better of course.
People go outside themselves to create this revolutionary piece of hardware, even better than anything that already is there. They even succeed in placing their brainchild in the shops- Only to have forgotten one or two essential practical things.
In a next life I think I'll start to collect these objects myself. For now I am very happy with sites like Neatorama that once in a while present these neat gadgets to us. :-)