Karabiner Model 31 (aka Schmidt-Rubin K31)

Bolt Action, 7.5X55mm Swiss, 6 round

Data

Information

This rifle has the following marks:

• Inspector Mark for (Major Mühlemann 1913-1941)

• Pressure Proof Test Passed

• Refurbished in 1955

• + sign indicating repairs were made

Close Up Views

Visible Numbers and Markings

Century Arms International import mark

This tag is the last person the rifle was issued to.  Its located behind the butt plate.  Tried to decipher it but no luck. 

Examples of K31 ID tags can be seen here.

Stock Cartouche

History

K31
From Wikipedia, the free encyclopedia

The Karabiner Model 1931 is a magazine-fed, straight-pull bolt-action rifle. It was the standard issue rifle of the Swiss armed forces from 1933 until 1958, though examples remained in service into the 1970s. It has a 6-round removable magazine, and is chambered for the 7.5x55 Swiss (also known as Gewehrpatrone 1911 or simply "GP11"), a cartridge with ballistic qualities similar to the .308 Winchester cartridge.

The often quoted but incorrect name of "Schmidt-Rubin" comes from two designers: Rudolf Schmidt, who designed the action for Switzerland's 1889 and 1896 rifles, and Maj. Eduard Rubin, who designed the ammunition.

Although the K31 is a straight-pull carbine like many other Swiss rifles, it was not designed by Rudolf Schmidt (1832-1898) as he was not alive to do so. The K31 was a totally new design by Waffenfabrik Bern under Colonel Furrer, and the gun does not have the Schmidt-designed 1889 or 1896 action. The first 200 K31s were made in May 1931 for troop trials (serials 500,001 - 500,200), thus the model number of 1931.

Distinctions
The K31 is noted for its straight-pull action, meaning that the bolt is pulled directly back, then pushed forward to cycle the action between shots, rather than being turned and pulled back and forth, as in Mauser pattern rifles such as the K98k.

K31s are also noted for their amazing accuracy and quality. The Swiss considered individual marksmanship to be of utmost importance. Therefore, the K31 was made with tight tolerances and excellent overall craftsmanship. Many shooters are able to achieve one minute of arc with unmodified K31s. This means that a group of bullets shot at 100 yards will stay within a 1" diameter area, a group at 200 yards will stay within 2", etc.

Many collectors of the K31 have removed the butt plate and recovered a small slip of plasticized paper from beneath it. This slip contains the name and address of the Swiss citizen to whom the rifle was issued. In some cases, collectors have used the information to contact the previous owners, and have recounted the details of those encounters on a variety of collector's web forums.

Poor stock condition
The stocks of most K31s are almost always in poor condition, especially around the butt area. Most are very gouged and scratched. One theory for explaining this is that the Swiss soldiers would use the butts of their rifles as boot jacks for their cleated boots. They may have used the butts to clean snow and mud from their boots as well. Soldiers may also have carried the rifles in backpacks, with the buttstock exposed to the elements.

Another explanation for the poor condition of the stocks is that the Swiss soldiers would stick the butts of their rifles into the snow when they needed to put them down. When it was time to move out, the soldiers would kick their rifles (with their cleated boots) to dislodge them, as they had become partially frozen and stuck in the snow. This would also explain the discoloration from water damage on many stocks in the butt area.

These theories, however, are all speculation, as there is no hard evidence to definitively prove any of them. Collectors affectionately refer to the stocks as "beaver chewed" and "head bonkers".

The majority of K31 rifles were used during World War II in the "active service" (Aktivdienst), and were exposed to all weather conditions. After all repetition courses, soldiers took their rifles back home. Most of the rifles available today as surplus were used during training courses over many years through the late 1970s

Sights
The standard sights on a K31 are iron sights that can be adjusted for both windage and elevation. The rear sight is graduated up to 1500 meters. The iron sights are very capable, but are somewhat limited by the large size of the post (front sight), which covers approximately 8 MOA. This means that aiming at a very small target at long range is difficult. Mounting a scope is not easily done because of the design of the action, but there are specialized scope mounts available.

Availability
As a standard service rifle of the Swiss armed forces, the K31 was replaced by the SIG 510 in 1958. As of 2006, the K31 is readily available from most military surplus vendors. As noted above, the stocks are usually in average condition, but the barrel and bolt assembly are usually in very good condition.
 

Other web sites with information about the Karabiner Model 31

Swiss Rifles

Surplusrifle.com's articles on the K31

Modern Firearms entry on the K31

History and manufacturing information on Schmidt-Rubin pattern rifles

chuckhawks.com article on the K31

Manufacture Dates of Swiss Schmidt-Rubin Rifles

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