Can't help with which Combloc pistol design to get, I was never interested in any of them, Sorry.
But I did get to thinking about bottleneck pistol rounds, and while I don't consider the .32-20, .38-40 and .44-40 to be true bottleneck cases (if they are bottlenecks, then so is a mason jar,
) ,but I suppose they don't really fit anywhere else...
What got me wondering, is, in addition to the early bottle neck pistol rounds, what have we added that would be considered modern? And, I 'm specifically talking about semi auto pistol rounds here. .22 Jet and .256 Win mag are revolver and single shot pistol rounds. What do we have for semis in say the post WWII era?
.357 Sig is the hands down popularity winner..
.38/45 was a mildly popular wildcat, for a time, but is pretty much never seen any more.
I remember hearing about a .22/45 case somebody was trying to get going, saw an ad for the pistol, or conversion kit, don't remember the name anymore, but I do remember they wouldn't sell reloading dies, but wanted you to ship your fired brass back to them for them to reload. Never heard much after that, I think it bombed...
The only others I can think of off the top of my head that are "modern" are the .357 AMP and the .357 GWM (which is essentially the AMP formed from the slightly shorter .45 Win mag case)
Very high performance rounds, with specialized use and special guns not remotely in the duty/self defense class.
would the .400 or .440 CorBon count? I'll have to check, am not familiar with them...