All About Guns

Old School: Karabiner 31 by James Slaughter


Here’s a fun anecdote about the Swiss Army: The story goes that when asked what they would do if invaded by a force twice their size they said, “Shoot twice and go home.” Depending on whom one asks, this conversation took place either just before World War I or just before World War II, but it doesn’t really matter either way. The story was designed to convey an attitude. The Swiss Army is small if you only count the active portion. However, for an invader the Swiss Army is a potential guerrilla nightmare, considering the terrain and the well trained populace amongst whom shooting is a national pastime. Considering the government literally handed out firearms and ammunition to the public, this shouldn’t come as a shock.

In the event the Swiss needed to call on themselves during the World War II years, the Karabiner 31, or K31, would’ve done most of the work. The K31 stood out among World War II small arms for many reasons, but its most noticeable feature is its straight-pull action. The straight-pull action was certainly not unique among military small arms. Switzerland had extensive experience with straight-pulls, but rifles such as the Ross and Lee Navy, though not widely issued, and now somewhat forgotten, were issued by Canada and the United States Navy respectively.

Superbly crafted, the supply of original K31’s has almost completely been swallowed up by the civilian market in the U.S. and Switzerland. The odd-looking hook below the muzzle allows three or more rifles to be stacked, free standing in camp.

Unlike the Ross and Lee Navy, the K31 never saw real action in the hands of the troops to whom it was originally issued. However, there’s no reason to suspect it wouldn’t have performed magnificently had it been called upon to do so.

The standard-issue K31 was the last of the Swiss service straight-pulls. The K31 was chambered in 7.5×55 Swiss (GP 11), which was a very modern cartridge for its era with comparable ballistics to the 7.62 NATO round. Fed from interesting six-round stripper clips made of compressed paper and metal, the K31 sported an easily detachable six-round box magazine. Like the SMLE, which also had an easily detachable magazine, spare magazines were more the exception than the rule. The GP11 fired a 174-grain, boat-tailed bullet at about 2,550 fps on average. Generating almost 2,550 foot-pounds of energy, the GP11 clearly stood out for its effectiveness amongst older cartridges still widely in use during World War II, such as the 7.92×57, 7.62x54R, and 7.62×63. Further, in the K31, the GP11 round is actually quite pleasant to shoot.

If you’ve never fired a straight-pull, especially a K31, one feature of the action is genuinely going to surprise you the first time you try one; it’s quick. While the straight-pull action isn’t as fast as a semi-automatic, it’s clearly faster and far less awkward than even the notoriously speedy SMLE. The K31 straight-pull bolt is also amazingly slick due to its combination of design and craftsmanship. When trained on the K31, a good shooter can manage a healthy rate of fire of up to 20 rounds of aimed fire per minute.

Yanking on the bolt handle rotates the two-lug bolt head via the cam path cut in the bolt body.

Germanic small arms are notoriously well crafted, but for standard-issue weapons, the K31 is a stand-out among them. Compare one to a K98 side-by-side and head-to-head, and you’ll see the difference. As issued, the common K31 demonstrates an unusually high degree of fit and finish, and an unissued K31, especially with a walnut stock, looks more like an extremely unusual, but high-end sporting rifle. It’s a complex rifle with a number of unusual features beyond the intricate clockwork bolt, including the barrel installation system that requires specific training and knowledge. There are but a handful of gunsmiths in the United States who will install new barrels on a K31. To offer an idea of how well made these rifles are, it has been estimated that the production cost alone of a standard K31 would approach $2,500 per unit if made today.

Performance on the range is also exemplary. While the effective range of the K31 chambered in 7.5 Swiss is often cited in the 600m range, in reality, it’s effective up to 800m with little difficulty and beyond that with tuned rifles and match or handloaded ammunition. It’s popular in vintage rifle matches here in the U.S., and it’s widely popular in other countries as well, but again, this isn’t surprising due to its quality, craftsmanship, and effectiveness. Surplus ammunition is getting harder to find and more expensive than it once was, which is a shame. Most of the GP11 imported into the U.S. was made by RUAG, and even the common ball ammunition approached match standards. Handloading components are now easy to acquire in the U.S., and if you have enough patience, time, and money to invest in Berdan reloading components, the Swiss GP11 brass is very high quality and lends itself to reloading.

There are more exotic variants of the K31 out there if you want to look. There are a couple of sniper models and a number of match-tuned rifles out there as well. Accessories are sometimes challenging to find, and expensive, but generally as well made as the rifles.

One last note: When (you want one even if you don’t know it yet) you buy a K31, look under the buttplate. Swiss soldiers often put their name and information on a slip of paper and secured it there. Some of them are still living, and occasionally have been known to respond to communication about their rifles.


Caliber: 7.5×55 Swiss
Overall length: 43 inches
Barrel length: 25.6 inches
Weight (unloaded): 8.8 pounds
Magazine capacity: 6 rounds (standard)
Effective Range: 600 M+

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