Notes: This rifle was designed by two Belgian brothers named Nagant and a Russian Army colonel named Mosin. The 7.62mm Nagant cartridge was designed for use in this weapon (though at the time of it’s design, it was known as the 3-Line cartridge). The weapon has an unusual safety; it is engaged by pulling the cocking handle back and rotating it backwards. Many variants were made over the years.

The first model was the M-1891; it uses a removable socket bayonet. The sights were calibrated in the obsolete Russian measurement system of arshins (one arshin is about 711 mm), but in 1917 most of them were converted to metric sights. The bayonet, though removable, is designed to be on the rifle; in fact, the balance of the M-1891 is so affected that the sights must be re-zeroed if one intends to use the rifle without the bayonet. The M-1891 is almost an obscenely-long weapon, at 51.9 inches, though this did allow for an incredible 32.3 inches of barrel length. Receivers were of heavy steel, and a ramp-and leaf sight rear sight and a front bead sight were provided for aiming on original M-1891s. The stock was straight-wristed. Experience in the Russo-Japanese War of 1904-05 showed that the sights worked poorly at short ranges, and therefore they were re-worked. At the same time, some minor changes were made to the mechanism and stock. Issued in 1910, this version was the M-1891 Type L. (It is identical to the standard M-1891 for game purposes.)

The M-1891 Cossack Rifle is a version of the M-1891 with a shorter 29.9-inch barrel, sling slots moved to the side of the stock and fore-end, and a modified cleaning rod. It was designed specifically for use from horseback. This version was built until 1914, with assembly continuing until 1915. The M-1891 Dragoon is essentially the same rifle with a different cleaning rod, but otherwise virtually identical to the Cossack rifle. Both had special weighting so that aim was not disturbed whether or not a bayonet was attached. The Dragoon became the standard infantry rifle in 1922, and production continued until the early 1930s.

The M-1907 carbine used an even shorter 20.05-inch barrel. It was specifically designed for the Tsar’s Army artillery and cavalry units. The stock had such a long fore-end that a bayonet could not be attached. Originally, the sights were graduated for arshins, but with the advent of the Spitzer bullet, the sights were replaced with metric sights graduated for longer ranges. (Some sources call this version with modified sights the "M-1910," but this nomenclature is generally regarded by most experts as incorrect.)

The M-1891/30 is a modified Dragoon rifle with the receiver body changed from a hexagonal shape to a cylindrical shape. This was done to simplify manufacture. In addition, the rear sights were changed from leaf-type to a tangent-type, and the front sight was changed from a barleycorn type to a more modern hooded post. Sling slots were added to the stock and fore-end. A new bayonet along with a more secure bayonet lug was designed for the M-1891/30. Barrel length was still an astonishing 28.75 inches. The M-1891/30 is perhaps the most numerous of all of the M-1891 series, with some 17.5 million being built (mostly just before and during World War 2). The M-1938 carbine was essentially a shortened M-1891/30, with 20.05-inch barrel and the ability to use the same bayonet as the M-1891/30.

The M-1891/30 Sniper’s Rifle was made by taking the best-performing rifles from production batches of M-1891/30s, adding a mount for the PU or PE telescopic sights (both of which were modified Zeiss designs, with the PE being longer and having a 4x magnification, while the PU was shorter and had a 3.5x magnification), and given further treatment to ensure smooth operation of their actions. The normally straight bolt handles were also turned downward so as to not interfere with the scope, and a slot was cut in the side of the stock for this down-turned bolt handle.

The M-1891/30 Silenced Rifle is a rare and odd variant of the M-1891. Designed for use with special "partisan" sub-loaded ammunition, these rifles were never large in number and even recorded uses of them are rare. They were to be fired only with the special subsonic ammunition; if normal ammunition is used, the rubber-baffle silencer would be ruined in as little as 3 shots. Even with subsonic ammunition, the life of the silencer may have been as little as 30 shots.

Starting in 1943, experiments began to affix a permanent folding bayonet to the M-1938. By 1944, a Semin-type folding cruciform bayonet was settle upon and production began. Unfortunately, it was quickly realized after World War 2 that the M-1891 series was obsolete, and production stopped shortly after the war. Production did, however, continue in other countries, most notably China, long after this point.

During World War 1, the Austro-Hungarians captured mountains of M-1891s and M-1891 Cossack rifles on the Eastern Front. Most of these were used without modification (as the Austro-Hungarians also captured mountains of ammo), but a considerable number were converted to fire the 8mm Lebel round which was one of the Austro-Hungarian standard rifle rounds. Some were also modified to use Austro-Hungarian bayonets. Like the Austro-Hungarians, the Germans also captured large amounts of these Russian rifles and ammunition, but some of these were also converted to use the standard German service cartridge (8mm Mauser in this case). Captured German examples were far more likely to have been modified to use German bayonets.

The Poles also used the Mosin-Nagant starting in the 1920s until its subjugation by the Nazis in World War 2. Theirs were highly-modified, chambered for 8mm Mauser ammunition, designed for German-style bayonets, and having barrels 23.6 inches long. These rifles were called the M-91/98/25.

So many Mosin-Nagants were built, and the design so hardy, that they can still be regularly encountered today in the hands of various insurgents, rebels, hunters, and even in some armies.

Notes: Though this battle rifle had been under development since 1931, it was not until 1936 that Simonov (better known for the SKS carbine) developed a weapon that worked well enough to put into production. Unfortunately, the AVS-36 was never trialed properly, and in battle, its shortcomings became obvious. The AVS-36 was hampered by an overly-complicated gas operation system that fouled too quickly since it let dirt and dust in too easily. In addition, the weapon was much too light for the cartridge when fired on automatic, and muzzle blast was far too great due to a poorly-designed muzzle brake. The AVS was replaced by the Tokarev SVT-38 in 1938.