I think it's an answer to a non-existent problem. But what the heck, a lot of guns and calibers fall in to that category or come close.
Back when I was in High School, there were some interesting wildcats floating around. 22-30Carbine (30Carbine necked down to 22) fell between 22 Hornet and .222/.223 class cartridges in power, you could buy carbines chambered for it. IIRC both Plainfield and Iver-Johnson produced them. Would probably make a nice mid-range varmint cartridge, re-loadable, more than you can say for the latest rimfire magnums. Also 17-223. you guessed it .223 necked down to .17. Pretty impressive terminal ballistics on a lot of things, I saw some metal plates that were pretty neatly punched by "regular" fmj bullets. They were IIRC 4500 fps muzzle velocity, so they were pretty rough on barrels. Both cartridges were allegedly being tested by the Marines.
You reach the point of diminishing returns pretty quickly in pistol ammunition and even sooner in revolvers.