Paul McC: Buenos Morning to ya. You mentioned building or wanting to build a 30 or 32 caliber pistol on a 223 case base, citing Cooper's work building a 9mm on that case.
Cooper wasn't the only one who did that. It was the only alternative a number of eyars ago for folks who shot 9mm Largos but couldn't get the loaded cartridges or brass and the slightly rimmed 38 Supers wouldn't chamber properly.
There are some cartridges out there that may reduce the amount of effort you need to put into your project. You mentioned a 32 S&W Long caliber - the case on that cartridge, I believe, is about as long as the 30/7.65mm Luger, quite a capable and accurate round. It operates within Luger pistol toggle action pressures, so it is not a magnum round by any means but will throw a 93 grain .310 bullet to 1280'/sec, original loading. Now, that's a 32 caliber. For 30 caliber, you have the 30 Mauser/7.62x25mm Tokarev cartridge, which may be a bit longer than the 32 S&W long, that takes a .308 diameter 88 grain bullet but as fast as 1400'/sec. Both cartridges are, literally, based on a 9mm case head, as the 9mm was an offspring of the 7.65/30 Luger.
If you are not interested in those, there is a new NAA (North American Arms) cartridge in 32 caliber - it is a necked down 380 auto round that fires a 32 acp bullet out to about 1200'/sec. The 32 (310 dia) caliber pistol bullets in jacketed form that I am aware of go from 60 grains to 71, 73, 77 and 93 grains. In 30 caliber (308) you can find them at 85, 88, 100 and up. Hope this helps and good luck. Mikey.