Colt Pocket Hammerless in .32 ACP, Seacamp .32 ACP comparison.
Colt Vest Pocket .25 ACP compared with KelTec P3AT, in .380.
As you can see the 108 year old Browning design is still a bit smaller than one of the smallest of the current .380s.
To make a really small gun, start with the cartridge, or if you were John M. Browning, invent one.