The .320 can be viewed as a centerfire version of the .32 Rimfire, albeit less powerful.
Certain types of .32 Short Colt cartridges had a slightly different-sized rim.
On some guns, these .32 Short Colt rounds will fit and cycle properly.
[2] Due to the popularity of the .32 Long Colt and, later, the more accurate .32 Smith & Wesson Long, the older .32-caliber cartridges, such as the .320 and the .32 Rimfire, declined in popularity and were eventually more or less obsolete by the 1920s.
In Brazil, both .320 guns and ammo (double-barreled, side-by-side pistols) were made up to the 1960s.