The Zielfernrohr Karabiner 55 (lit. scoped carbine 55) is a Swiss sniper rifle. Essentially a variant of the K31 carbine, the ZfK 55 was meant for use as a designated marksman or sniper weapon and was the standard sniper's weapon in Switzerland for a time.


The Swiss had already been experimenting with optics such as side-mounted periscope mounts during World War II for use in rifles like the K31, as the Swiss needed a scoped rifle at some point. The first attempt to produce such a weapon was known as the ZfK 51 (Zielfernrohr Karabiner 51), essentially a scoped K31, but was found to be slightly flawed and was rejected; as such, a new weapon had to be designed.

Most countries such as the United States would achieve the above goal by taking a normal rifle and attempting to mount a scope as unobtrusively as possible; what the Swiss did was to purpose build a rifle using the same action as their service rifle but making some changes to make it an ideal sniper's weapon.[1] This design concept led to the production of the ZfK 55.

Production began in 1955, with the weapon being adopted the same year; production ended in 1959 with 4,150 examples built.[2] The rifles have since been deemed surplus and declared obsolete, with most surviving samples being either museum pieces or collector's items.[1]

Design DetailsEdit

Main article: K31

The ZfK 55's design and action is practically almost identical to what is found on the K31. However, there are a few key differences between both weapons; few parts also interchange between both weapons.

The most notable visual differences between the K31 and the ZfK 55 were the addition of a scope, a distinctive ported muzzle brake and a bipod on the ZfK 55; the scope used on the ZfK 55 is a Kern & Sohn 3.5×22 scope with an effective range of approximately 800 metres (2,600 feet; 870 yards).[3] The muzzle brake on the weapon is said to be inspired by the muzzle brake of the FG 42. The weapon also has a front iron sight with a slanted track for precise windage adjustment. The bipod is spring-loaded, although it is not exactly strong enough to keep the weapon standing on its own. Another rather notable difference was the addition of checkered grips on the ZfK 55.[2]

The most notable mechanical difference between the K31 and the ZfK 55 was the action; the action on the ZfK 55 is canted about 15° clockwise. This was done for a reason; this was to allow the scope on the rifle to remain centerline while still allowing its user to reload the weapon using stripper clips. This was a novel solution to the scope problem on most rifles of the time, where the solution most came up with was the mount the scope off to the side of the receiver or mount it centerline but ditch the use of stripper clips entirely; this solution offered the best of both worlds with the only real disadvantage being making the weapon more expensive to produce as a whole.[4]

The ZfK 55 uses the same six-round detachable magazines as the K31. However, the magazine is canted about 15° counterclockwise to line up with the canted action. To accommodate the canted action, the bolt handle is bent slightly at one end. Similar to the K31, the magazine was not meant to be replaced on the field, with stripper clips made out of a unique formed phenolic resin-embedded paper being used instead to refill the magazine.

Other than the above, most other specifications are identical to the K31.[5]


Just like the K31, the ZfK 55 takes 7.5×55mm Swiss rounds, also known as the Gewehrpatrone 11 (Gw Pat 11). The cartridge was designed by Colonel Eduard Rubin.


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