While M1895s were used in numerous countries, most of them were produced and used in Russia. Adapted into service by Tsarist Russia in 1895 and retained by the Soviet Union, they were partially replaced in service by the Tokarev TT-33 in the 1930s, but not completely retired from frontline service until the adoption of the Makarov pistol in 1952. Afterwards, they were relegated to use by second-line troops and security troops.
Curiously enough, antique Nagant revolvers are still in use in Russia: postal security still used them until 2003, while bailiff security services only retired theirs in 2009.
The Nagant's most distinctive feature is that it is a gas-seal revolver. The cylinder pushes forward slightly as the hammer is cocked, engaging the elongated cartridge neck with a conical ring at the back of the barrel to form a gas-tight seal. This renders the weapon quieter and more powerful than a conventional revolver, and also removes any possibility of injury from escaping gas at the cylinder gap.
A considerable trade-off with this system was the trigger pull, measured on some pistols as over 20 pounds in double-action and around 15 even in single-action. In addition, because the neck of the cartridge protrudes beyond the front of the cylinder and expands during firing, it can be difficult to extract spent casings: while an extractor is provided, it can require use of a hammer.
The mechanics of the weapon forced the use of a loading gate rather than a swing-out cylinder: while the Nagant might appear to have a cylinder crane, this is actually just an extractor rod that swings out to assist in removing cartridges, lining up with the second-from-top chamber on the right.
The whole system, intended to make full use of propellant gas, was quite complicated. It made the Nagant one of the rare revolvers capable of mounting a suppressor. This feature was actively used by NKVD and special forces of the Red Army. The suppressor, named the Bramit device, was developed by the Mitin brothers, and could be mounted on the barrel when desired.
The 7.62×38mmR Nagant round is fairly unique in design and was only ever used by the M1895 revolver. The cartridge is slightly longer than the revolver's cylinder and the bullet is seated completely inside the casing, in a similar manner to the later Cased Telescoped (CT) ammunition concept. In this case, though, the extended mouth of the cartridge is so that it can interface with a ring that protrudes from the back of the barrel when the cylinder moves forward, forming a gas-tight seal.
Ammunition for the Nagant is rare, even more so outside Russia, and Nagants in the US often use an aftermarket cylinder allowing them to fire the more common .32 ACP cartridge. This does however render the gas-seal system entirely superfluous, and can be dangerous with high-powered loads.
Cheaper single-action only variant. Production ended around 1918.
Double-action variant. Most examples of the "Private's Model" were later upgraded to this standard.
Short-lived variant with a swing-out cylinder. Never adopted by the military and sold poorly on the civilian market.
Nagant wz. 30 & wz. 32
Polish Nagant clones produced by Fabryka Broni Radom, mostly distinguished by a slightly shortened barrel and redesigned sights.
.22 LR civilian revolver-carbine using a Nagant action, manufactured by Izhmash.