Mechanix Illustrated has an article online, first published in 1957, about “revolutionary” The Dardick revolver and its triangular rounds (Trounds).

I wonder how reliable those guns were. I imagine that the design would have combined and amplified the feeding problems associated with autoloaders and the heavy trigger pull of double action revolvers.

[ Many thanks to Sven (Defense and Freedom) for emailing me the the info. ]