A silencer would not be effective on most stock revolvers because of the forcing cone gap.
Is that Elvis..
I remember seeing a photo of a Tunnel Rat at that time in a major magazine. It mentioned the silenced revolver designed to protect his ears.
I just went to the web site. THAT first photo is the photo I saw back in the 1960s.
The only revolver that I was aware of that was made in large numbers that could be effectively silenced was the M1895 Nagant. It uses a special cartridge where the projectile is recessed within the brass and a mechanism where the cylinder is moved forward when firing which forms a “gas seal”. Other revolvers allow a significant amount of gasses and noise to escape from the firing chamber.
The Vietnamese modified significant numbers of these for use in underground bunkers and the KGB used them for political assassinations. I have several of them but of course no silencers. The original Nagant brass is a little hard to find so I usually use Starline 32/20 brass using special dies to form it to fit the Nagant revolver. It forms no gas seal but works great.
First video shows how effective a silencer is on the Nagant revolver. Second video shows reloading process using Starline 32-20 brass.
https://youtu.be/UKoCIeqVHIY?t=197
This has more to do with flash signature mitigation than sound mitigation. Same today.
The training area for “Tunnel Rats” was in Garden Canyon, Ft Huachuca, AZ. The final FTX for intel students back in the 70’s was a mock prisoner facility built on top of the tunnels for the tunnel rat course.
Very strange times and very strange places.
If I recall, when we went out on some special op, they issued us High Standard pistols with integral suppressors. They were semiautomatics and I believe the magazine held 10 rounds. The ammo that the issued was subsonic. We couldn’t keep them though and had to turn them in at the end of the op.