Use With Suppressors
As a general rule, revolvers cannot be effective with a sound suppressor ("silencer"), as there is usually a small gap between the revolving cylinder and the barrel which a bullet must traverse or jump when fired. From this opening, a rather loud report is produced. A suppressor can only suppress noise coming from the muzzle.
A suppressible revolver design does exist in the Nagant M1895, a Belgian revolver used from 1895 through World War II. This revolver uses a unique cartridge that extends beyond the tip of the bullet, and a cylinder that moves forward to place the end of the cartridge inside the barrel when ready to fire. This bridges the gap between the cylinder and the barrel, and expands to seal the gap when fired. While the tiny gap between cylinder and barrel on most revolvers is insignificant to the internal ballistics, the seal is especially effective when used with a suppressor, and a number of suppressed Nagant revolvers have been used since its invention.
There is a modern revolver of Russian design, the OTs-38, which uses ammunition that incorporates the silencing mechanism into the cartridge case, making the gap between cylinder and barrel irrelevant as far as the suppression issue is concerned. The OTs-38 does need an unusually close and precise fit between the cylinder and barrel due to the shape of bullet in the special ammunition (Soviet SP-4), which was originally designed for use in a semi-automatic.
Additionally, the US Military experimented with designing a special version of the Smith and Wesson Model 29 for Tunnel Rats, called the Quiet Special Purpose Revolver or QSPR. Using special .40 caliber ammunition, it never entered service, at least officially.
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