Oh HorseyPOO!!!
Parker Ackley liked the 23 caliber. He even invented the 230 Ackley Magnum.
Barrels are available from Pac Nor, in several "23 caliber" sizes. some are .230", and others are .236"
Anyhoo, I really do think that if the gun makers would introduce a round in this diameter it would sell like hotcakes, I can see variations in both bolt and semi-auto actions. (Witness the blistering success of the 204 Ruger).
People are starving for something truly new.
The gunmakers should give it to us.