Sako M39 Mosin Nagant Review

Finnish-made Mosin Nagant M39s are considered by many experts to be the best of the type. Of them, those produced by Sako are arguably the best of the best.

July 07, 2020 By Joseph von Benedikt

Several years ago I reviewed a Valmet-made M39 here in “The Shootist.” It performed superbly, and I was rather sure I’d never find a Mosin Nagant I liked more.

Then I found the Sako version reported on here. It is without doubt the nicest Mosin Nagant I’ve had the pleasure of handling, at least in terms of build quality and retained condition.

Engineered by the Finnish Civil Guard and adopted by the Finnish Army on 14 April, 1939, the M39 is a much-improved derivative of the Russian-designed M1891.

Importantly, every M39 is built using an M91 action. According to Brent Snodgrass and Vic Thomas’s excellent article “The Claws Of The Lion: The Model 1939 Rifle,” “The bolt, magazine assembly and portions of the trigger were [also] retained….” However, the barrel, stock, and hardware, including sling connections, sights, nose cap, and so forth were all replaced.

Changes to the stock include the use of a pistol grip, a heavier profile in areas of the M91 prone to breakage, and the use of warp-resistant Arctic birch. Two different types of sling attachment points were incorporated and made the M39 equally suited to use by infantry or mounted troops.

Interestingly, earlier Finnish adaptions of the Mosin Nagant utilized a bore diameter of 0.3082 inch. To make the M39 compatible with captured Russian ammo, barrels were reamed to 0.310 inch. Twist rate was also changed, to 1 turn in 10 inches rather than 1:9.5.

Because wartime demand delayed retooling, M39 production was slow, and the first Sako-made M39s were fielded in the spring of 1941. One source suggests that Sako delivered about 66,500 M39s to the Finnish Army between 1941 and ’45 and about 10,500 to the Civil Guard. Total wartime production of M39s, from all makers, tallied 96,800 rifles.

Mechanicals

Operation of the Mosin Nagant is in general very familiar to shooters, so I won’t go into detail here. In short, the design features a rotating push-feed bolt with dual, opposing locking lugs; a single-stack, non-detachable magazine with an interrupter to prevent double-feeds; and a short, straight bolt handle.

The ladder-type rear sight is quite sophisticated, enabling fine adjustments to 800 meters and coarse “volley fire” elevation to 2,000 yards. As for the front sight, it’s stout and provides fine windage adjustment courtesy of dual side screws.

Provenance

Unlike many vintage war-surplus rifles, it’s no struggle to date this rifle. While there’s no telling when the original octagon receiver came out of Russia, the date the rebuilt rifle left Sako is plainly stamped: 1944. Judging by its condition, it never made it into combat. I found it while prowling the used-gun treasures in the Brownells retail shop. Because of its excellent condition, I didn’t haggle over the price. The cartouches, proof stamps, and other marks are all present, clean, and correct. I’d say this rifle was quite a find.

Rangetime

As much as I love the history and superb craftsmanship behind these Finnish battle rifles, like Col. Townsend Whelen I find accurate rifles to be the most interesting. My Valmet-made M39 is a real shooter, and I was intensely curious whether the Sako version would measure up. So I gathered a stack of noncorrosive 7.62x54R ammo made by Barnaul and Lapua and headed to the range. My eyes aren’t what they once were, so I pasted six-inch black Birchwood Casey bullseyes on big white backgrounds and sprayed the rifle’s iron sights with Birchwood Casey sight black to eliminate glare. Then, I bore down on the sandbags and did my best.

Since Finnish 7.62x54R ammo utilized a 200-grain projectile at about 700 meters per second (roughly 2,300 fps), which is slower than most of the Russian loads, most M39s hit high at 100 yards. The Sako is no exception. My first Lapua 185-grain MEGA bullet clocked over 2,500 fps and impacted about 9.5 inches high. Maintaining my six o’clock hold on the black bull, I fired again, then a third time.

To my astonishment, the three bullets made a cloverleaf that measured 0.48 inch, center to center. The next three-shot group measured 0.98 inch. Although hot barrels and full-length wood stocks with constrictive metal barrel bands don’t play well together, I fired a third group without allowing the barrel to cool because I was curious to know whether point of impact would shift and groups would open up.

My third group—with the barrel quite hot—measured 1.71 inches, indicating that either accuracy does indeed deteriorate as the barrel heats or my eyes were getting tired—or both.

Lest you think it was an anomaly, that 0.48-inch cluster wasn’t even the best group of the day. A bit later, Lapua’s 123-grain FMJ load posted a 0.35-inch three-shot group.

Both Barnaul loads I tested averaged just less than two MOA. One, a 203-grain softpoint load at about 2,200 fps, impacted precisely on point of aim.

Of the many Mosin Nagant rifles I’ve fired, my Sako is the easiest to shoot accurately.Finnish rifles are known for smooth, reliable function, and the Sako M39 is no exception. It fed and fired everything I ran through it comfortably and without hiccup.