Mosin Nagant 'Three Line' Rifle M1891

After a sound trouncing during the Russo-Turkish War of 1877–1878, Russia decided it was time to get modern and arm her troops with repeating rifles. A relatively unfriendly design war was consequently fought with thorough zest, with elements of rifles by Capt. Sergei Ivanovich Mosin and Léon Nagant eventually combined and became the трёхлинейная винтовка образца 1891 года, or “Three-Line” Rifle M1891.

Three-line referred to the caliber, which was nominally 0.3 inch. That’s measuring the bore diameter before rifling grooves were created. At the time, in Russian rifle speak, a “line” denoted 0.10 inch. The cartridge designed for this rifle also wore the Three-Line name and was designated the Трехлинейный патрон образца 1891 года, or Three-Line Cartridge Model of 1891. When Russia later adopted the metric system, it was redesignated. Today, it’s the 7.62x54R.

When it came to numbers and measurement systems at the time, Russia was a many-faceted nation. In addition to the rifle being designated using the inch-based Three-Line system and the cartridge leaning metric, the sight was graduated in arshins.

What the heck are arshins—or, more appropriately, arshini? According to my good friend and Firearms News writer David Fortier, “Arshins are part of a native system of weights and measurements utilized by Imperial Russia. One arshin equals exactly 28 inches. So if a target is 500 yards distant, it is equal to 642 arshini.”

Put into service in 1891, the M91, as I’ll call it, was a reliable and relatively accurate infantry arm. It features horizontally locking, dual, rotating lugs; a multi-piece push-feed-type bolt; a magazine interrupter to enhance reliability; a five-round magazine; stripper-clip compatibility; and an 80cm (31.5-inch) barrel. It was rated effective to 500 meters (550 yards). The arshin-marked rear sight, when stood up ladder-style, was marked to 3,200 meters for use in volley fire.

As Fortier pointed out, the original M91 saw use in a plethora of conflicts, including the 1904‑05 war with Japan, the Great War, the Revolution of 1917, the Russian Civil War, and others.

Over the decades, some 37,000,000 Mosin Nagants were built in myriad different guises. By the M91’s first use in the Russo-Japanese War, about 3,800,000 had been manufactured.

Modifications and refinements continued to be made, resulting in the type used for this column. It’s a 1916-dated Izhevsk-made M91 with all matching numbers, including the receiver and barrel dates, and displaying the last of the refinements like the late Type-4 barrel bands.

From 1891 until 1908 Russia employed heavy 13.7-gram (210-grain) roundnose FMJ projectiles, and the arshin-marked rear sights were calibrated for it. Maximum distance of the volley-fired standing-ladder rear sight was 2,700 arshini. In 1908 a lighter 9.61-gram (148.3-grain) pointed bullet was adopted, and the sight was recalibrated to match. Maximum distance then became 3,200 arshini. The standing-ladder leaf took on a curved shape and was designated the Konolavov, after its designer.

---

In the late 1920s, a modified version of the M91 was adopted. Its barrel was 7cm (2.8 inches) shorter, and the gun featured an improved magazine interrupter, a more robust hooded front sight, and other minor changes. Many of the M91s were converted, and from that time forward, all Mosin Nagants manufactured were of the M91/30 design. Original, untouched M91s are much more rare today.

Mechanicals

To load an M91, open the bolt and thumb cartridges into the magazine, being careful to stack them with each succeeding rim in front of the previous one. Interestingly, you cannot load five rounds and not chamber the top cartridge when you close the bolt. If you wish to close the bolt on an empty chamber, load just four rounds. Pressing them down through the faint “click” to engage the magazine interrupter will enable you to close the bolt without the top round in the magazine being inseted into the chamber.

To chamber a round, simply work the bolt briskly. To engage the safety, draw the knurled cocking piece at the rear of the firing pin assembly firmly rearward and rotate it an eighth of a turn counter-clockwise. A catch in the bottom rear of the magazine box allows the magazine to be emptied without inserting every single cartridge into the rifle’s chamber.

Provenance

I found the rifle shown here in Brownells retail shop in Grinnell, Iowa. It was part of a modest estate collection of foreign military arms.

While I was drooling over a Sako-built Finnish M39 Mosin Nagant (which I also purchased), Fortier pointed out that the M91 was an even cooler rifle. It took a bit of convincing before I ceded his point, but the more I examined the rifle and the more I learned about it, the more I liked it.

Like I said earlier, it has all matching numbers and matching barrel and receiver dates. And it came with the sling and a bayonet. Obviously, it’s too young to have taken part in the earlier conflicts fought with M91s, but it may well have seen action in every war beginning with World War I and the Revolution of 1917.

Rangetime

After giving the gun a thorough bore scrubbing, I fired two consecutive five-shot groups at 100 yards with Arno Barnaul and Lapua ammunition. Candidly, it wasn’t accurate and tended to sprinkle shots into groups ranging from 4.00 to 8.00 inches. However, it shouldered, aimed, and balanced beautifully, and the crisp, fine sights were easy to use. Feeding was 100-percent reliable.

I love all vintage firearms, and there’s no denying the allure of a long, sleek Russian battle rifle, especially one built while the Czars still reigned and as revolution accelerated.