I'm sure that Malcom meant a .32-20.
There WAS a .32-30, but it was a rifle cartridge introduced in the Remington-Hepburn rifle in 1884.
I've seen various misprints in books over the years, referring to a .44-44 when clearly .44-40 was the caliber, and somewhere not long ago I saw reference to a Colt Single Action Army in .32-30 --- clearly a misprint.
The .32-20 is larger than other .32-caliber pistol cartridges, so I can understand how Malcom would say it was, "... bigger than a .32. But it's not as big as a .38."
A clumsy way of saying it's longer than other .32 pistol cartridges.
The .32-20 is still available today in rifles (it was introduced as a rifle cartridge in the Winchester 1873 before it found its way into revolvers) and in pistols.
Some love it, others figure the .38 Special or .32 H&R Magnum is just as good, if not better. It's something of a controversial cartridge, especially when its use for hunting is discussed.
Though it's taken a lot of deer over the years, it's far too under-powered for clean, reliable kills. Heck, plenty of deer have been taken with the .22 Long Rifle --- but no sane or responsible sportsman would suggest it as a deer round.
The .32-20 is a fascinating little round, though.
From about 1900 to 1940, tons of cheap, Spanish-made revolvers were imported into the U.S. Many of them were chambered for the .32-20 cartridge, apparently it was well-liked in Europe too. Many were outright copies of the Smith & Wesson revolvers of the time, but their fit and finish were much poorer.
Most of these revolvers had dubious metallurgy and were unsafe when they were new. They should not be fired today, with any load.