The Schmidt-Rubin Karabiner 31 (K31) was the last of a long line of Swiss designed straight-pull rifles going back to the year 1889, when the first of this action type was introduced into the Swiss military. In almost all of the straight pull systems unlocking of the bolt is accomplished by conversion of the linear movement, with little leverage, into unlocking and extracting. Straight pull mechanisms are usually a little more complex than turn bolt action rifles.

These first 1889 rifles were chambered for the uniquely Swiss 7.5 mm cartridge which was loaded with a copper jacketed projectile. The 1880’s was the period which covered the introduction of smokeless powder and jacketed projectiles that made small bores ranging from 6.5 mm up to 8mm practical. This meant a tremendous increase in range and accuracy of projectiles due to this new development.

The development of the Swiss rifles proceeded from the Infanterie Repetier Gewehr 1889 to the Gewehr 1911. The 1911 had a slightly shorter action but was the same overall length (51”) as the ’89. Its magazine capacity was reduced to six cartridges from twelve for the ’89. At this point in time the 7.5 x 55 mm cartridge which was loaded with a round nosed projectile was re-designed to use a spitzer projectile. This caused an increase in pressures and this spitzer loaded cartridge should not be used in the old ’89 Gewehr.
Shortly thereafter the Karabiner M1911 came on the scene. It used the same action as its longer version and served well into the Second World War, as did all of the rifles described. The 1889 was still used by older shooters who served in the ‘Ortswehren’ or Home Guard during World War Two.

This is perhaps a good time to pause and explain to the reader the Swiss concept of neutrality.

There were huge tensions between Switzerland and Germany during the 1870’s with Germany casting covetous eyes at the little nation with a view to incorporating it into the Second Reich. The Swiss unified their armed forces under a Federal system so that all equipment, armament and instruction would be done by the central authority.

In the years past the Swiss citizen had been required to provide his own arms. This was now changed so that the citizen-soldier kept his government issued arms, ammunition and uniform at home in case of call-up.

For instance, when World War 1 broke out the entire Swiss army was mobilized, they could field almost half a million men out of a population of approximately three and one half million.

Interesting Note

The Swiss hold a Federal Schutzenfest every five years. The last match attracted over 72.000 competitors which is one percent of the population. By comparison, if the same percentage showed up at Camp Perry 2.500.000 America citizens would shoot.

A ‘cult of marksmanship’ had also been encouraged. There were very few villages in Switzerland that did not have their own rifle range. Each Sunday they would reverberate with rifle fire as the good folk honed their skills.

In addition, the mountain passes which led into Switzerland were mined, and still are. Thousands of strong points with known fields of fire for mortars, machineguns and field artillery were constructed with the view that the Swiss were not about to give up their democracy easily.

World War II did not escape Switzerland entirely. Allied bombers often did not notice that they had crossed the Alps, and bombed what they thought was Germany. Hundreds of allied fliers were interned in Switzerland when they were forced to ditch there. The same treatment was applied to French foot-soldiers who escaped there following the disastrous 1940 German invasion of their country.

Nazi Germany considered Switzerland a thorn in their side. The Swiss were really Germans and should be part of the Third Reich. Having eluded the Second Reich, the Swiss had no desire to be added to Hitler’s conquests. The Germans had made at least three plans to invade Switzerland, but all were abandoned when wiser heads prevailed. The massive losses which the Swiss would have incurred and their irritating stubbornness assured that war would go on for a long time.. A three front war was not on the German agenda, even Hitler could see that.

Let us then go back to the early thirties which saw the adoption of the last modification and/or modernization of the straight–pull system. This rifle is the subject of this article, the Karabiner 31.

It was the same length as as the Karabiner 11. There were however important changes. The bolt unit had been drastically shortened with the locking lugs being moved up to the front of the bolt. It employed a detachable six shot magazine located directly in front of the trigger guard. The material used in the bolt knob was changed from a dark red colored synthetic to aluminum. The bolt knob color of the ’31 is one instant recognition feature across a Gun Show floor. The same cardboard/aluminum six shot ‘charger’ was used to load the magazine. Over 500.000 of these fine rifles were made, until they were finally declared obsolete in 1958 and replaced with a selective fire delayed blow back rifle, still in the same powerful 7.5 mm caliber.

Unfortunately for us collectors on this side of the pond, the Swiss soldier, at the completion of his basic training took his K31 home with him in the event of call-up, and many, when too old to serve, purchased their rifle from the government. For that reason, these rifles have been very scarce and thus rarely seen at the Shows. There were usually a fair assortment of 89ers and 1911 rifles around, but the K31 was a rare bird. My first one I got from Switzerland in the sixties and I still have one to-day, having always had a soft spot for Straight Pulls. It shares space in my cabinet with a Mk II Ross and a M1895 Steyr.

I note that they have begun to be advertised in the various gun magazines, so it would appear that the K31 invasion may have begun?

For that reason I would like to share some of my experiences I have had with the ’31 over time.

I see that boxer primed ammunition is being advertised. That’s great. I haven’t seen any yet. The only boxer primed stuff that has appeared, and that 20 years ago, was Norma and a batch made by Interarms. Current issue Swiss 7.5 is Berdan primed, and is beautiful, but hard to get, ammo. I still see the odd small batch of the old round nosed loads for the ’89 with beeswax around the case mouth, seems a shame to shoot that.

Reloading was actually quite easy. I found that once you had a set of dies, full length sizing of 284 Winchester brasses would work. Trim to 55 mm and make sure that when you seat your .308 diameter bullet it is deep enough in the case so that the ogive will not touch the leade (The unrifled area just ahead of the chamber before the rifling starts. Very small in K31's), or your bolt will remain open just a tad, and you will get misfires. I used .308 data and got excellent accuracy. If you wish, 5.5 mm Berdan primers also work, and it is no trouble to pop them with the tool RCBS sells. I believe Old Western Scrounger Ammunition in California has the primers for sale .

Some years ago, Mandall Shooting Supplies in Arizona advertised K31’s in .308 caliber, but the price, which I believe was $ 1000.00, made me shy away.

The Swiss have an interesting, and probably correct, way of working the bolt. They basically slap it open with the palm of the hand and close it the same way. Very fast, and the rifle does not leave the shoulder.

If you have a military K31, they made some 10.000 plus commercial ones, and want to know when it was made, just take off the butt plate and the year should be stamped there, and mine was stamped 1935. I have seen another target sighted one which was 1947. Anytime from ’33 to ’58.

Here in Ontario, Canada, there is a Swiss Rifle Club which is affiliated with our Dominion of Canada Rifle Association (DCRA) they all shoot K31s, many with complicated diopter sights. All shooting is at the standard Swiss 300 Meter range and using the Swiss issued target. Their ammunition is flown in from Switzerland, as many of the members still have to shoot their annual qualification. Other members may purchase ammo at reasonable prices. Club membership is open to all but the tough part may be finding a good K31.

The Club sure has their shoots well organized. A tent goes up immediately, Swiss flag on top, and the food preparation and registration of the shooters begin. All age groups are represented. One 80 years old plus gentleman (pictured below) let me try his diopter sighted K31. "Only accurate rifles are interesting" as a famous American shooter opined, and this octogenarian’s rifle was no exception.

 

Gentleman with diopter sighted K31

Disassembly of the K31 bolt (NO, NO, not that! is a common response from K31 owners) goes as follows:

1. Remove bolt assembly from rifle;
2. Pull back on the cocking ring and turn it so it rests on the back of the bolt between the fire and safe position;
3. Push forward and up on the cocking handle and remove it;
4. Turn bolt cocking ring. This releases the unit from the inner bolt and it may be removed from the bolt sleeve;
5. Turning the cocking ring and easing it forward releases the mainspring tension. The firing pin can now be removed and this unit disassembled;
6. Admire the workmanship that has gone into it!

Switzerland is the oldest democracy in the world. It is a country where the state trusts its citizens with the custodianship of the worlds’ most modern assault rifles, and does not fear them. The truism which states, "fear the government that fears your guns", does not apply to the Swiss.

They are only too aware that the reason they still have their independence is because they have the ability to defend themselves, and the willingness to give their lives in that defense.

As that eminently practical Italian civil servant, Nicolo Macchiavelli, said so many years ago about the Swiss, “... They are most armed and most free”. They still are.


Article Written by: Finn Nielsen