And one of them, the 1851 Nagant, had a mechanism that when the hammer was cocked, it would move the cylinder forward to seal against the barrel/forcing cone. So it must have been thought of as significant enough to make a difference audibly.
The mechanics of the 1892 Nagant revolver were not intended to keep the revolver quiet. Rather, it was to eliminate gas cutting and squeeze maximum velocity out of the cartridge (by not bleeding pressure off through the gap) from the then-new, but anemic smokeless powder.
The design just happened to lend itself quite nicely to being suppressed. It had both the benefits of a locked-breech single-shot, and of a repeater.
