Are you interested in firearms, both military and civilian? Did you ever wonder how such instruments worked? Why should I use x caliber over something else? Perhaps you found your grandfather's old rifle and want to know something about it. Even better, perhaps you want to node something about it and need a little guidance.

We are here to help.

e2armory is the home for people who want to write and discuss firearms from a strictly technical perspective. We are a completely non-political usergroup, so please note that political discussion will result in expulsion. Everything from the musket to the modern day battleship cannon is on the bill of fare.

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Everything from cleaning solutions to firing solutions.

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Switzerland entered the 20th century with a service rifle designed around 1889, the Schmidt-Rubin. This was a straight-pull bolt action repeater, and it fired a 7.5x53.5mm cartridge known as the GP90 (1890). Around 1905, Germany came up with a new military cartridge, with a pointed (spitzer) bullet and smokeless powder. Switzerland responded with the GP11 round (for Gewehrpatrone 1911) - a 7.5x55mm cartridge, with a 174 grain spitzer bullet of 0.3087" diameter on it that developed approximately 2640 fps. This round was used in rebarreled 1889 Schmidt-Rubins, in the 1913-introduced 1911 Rifle, and in the 1931 shorter K31. It continued in service until 1983, used in the StGw 57 (Sturmgewehr 1957).

The round develops energy between the American .308 Winchester and .30-06 Springfield cartridges, with a lower operating pressure. In its GP11 form, this round is extremely accurate, to the point that enthusiasts with K31 rifles and surplus GP90 cartridges are able to compete effectively with dedicated precision ammunition and target rifles, which speaks extremely highly of Swiss arms design and manufacturing. It can be had, as of 2015, intermittently in the US as GP11 surplus, although those cartridges are Berdan primed; and it is occasionally manufactured by companies such as Prvi Partizan and Wolf in modern Boxer-primed brass. It can be reloaded using standard 30-caliber (.308) projectiles.

It is likely referred to as 'Swiss' to prevent confusion with 7.5x54mm MAS, also known as 7.5 French.


In the United States, a decent .22 Long Rifle target pistol has generally (for the past couple of decades) meant a Ruger Mk II/III or a Browning Buckmark. For plinking and training, many manufacturers make .22LR versions of their popular full-sized guns. One notable exception around the turn of the century was SIGARMS, the US arm of SIG SAUER firearms of Germany and Switzerland.

By the 1990s, the SIG group included Hämmerli, which was (and remains) a manufacturer of high-end competition target pistols and rifles. SIG decided to get into the target pistol market. With the help of Hämmerli, they came out with the Trailside, a gun much cheaper than Hämmerli's products and intended to be more durable - suitable for casual use and, as the name implied, woods carry.

The Trailside is an autoloading, blowback operation .22LR pistol. It doesn't look nearly as 'space-age' as some of Hämmerli's more exotic competition guns, but it's still somewhat striking with a very square profile and a partial slide (akin to the Desert Eagle). Originally available with 4.5" or 6" barrels, the Trailside sold for between $400 and $600 new. It is based at least partially on the Hämmerli 208 - but where that gun has a parts count of over 135, the Trailside has 42 which explains why it was over $1400 cheaper. The Trailside is a very, very accurate pistol. When bought new they came with a proof target showing that they met spec - any gun unable to hold three-quarters of an inch groups at 25 yards was rejected and sent back.

SIG has since sold Hämmerli to Walther. The European version of the gun is still available as the Hämmerli X-esse (Xesse).


The Karabiner 1931 rifle - also known by its abbreviated name, the K31 - is a Swiss military rifle produced from 1933 through 1958. All extant guns (as far as I know) were made by Waffenfabrik Bern (Weapons Factory Bern) for the Swiss Army.

The rifle is chambered for the 7.5x55mm Swiss round, also known as the 7.5 Schmidt-Rubin (after an earlier rifle which used it) or GP11 (Gewehrpatrone 11) after the Swiss military designation of the round. The K31 was never used in warfighting, seeing as it was the rifle of a neutral country. In the 1940s and 1950s, Swiss reservists (i.e. most Swiss) were issued K31s to keep in their homes as their standard rifle.

Now that it's the future, the K31 was replaced back in 1958 by more modern battle rifle and assault rifles. These guns were collected and stored in Switzerland, until the Swiss realized what most countries with surplus guns have which is that you can probably sell them to American civilians for cash. So they have.

The thing about the K31 is that it is an extremely well-made gun, built for precision and marksmanship which is unusual in a general-issue military rifle. Also, as surplus, they can be had in the U.S. for around $300 if you're lucky. Finding ammo is a bit more of a PITA, but it's doable for around $0.50/round, and the surplus ammo is also of high quality - shooters report achieving 1 MOA with unmodified surplus K31s and surplus ammunition. That means that at 100 yards, all shots land within a 1-inch circle.

The guns weigh in at 4kg when empty, and have approx. 600mm long barrels. They are fed by a detachable 6-round magazine issued with the rifle - the magazine, receiver and bolt are all serialized, and as issued all matched. They are not disposable magazines, though - the K31 was loaded using phenolic stripper clips from above, with the magazine in the rifle. Everything about it was designed to be used with thick protective clothing, because hey, it gets cold in the Alps.

Probably the most distinctive feature on the gun is its action. Although it is a bolt-action rifle, the bolt is not rotated and then slid; there is a lever on the side of the gun that is pulled straight back to eject, and straight forward to load a new round and lock the bolt. There are cam-action grooves on the bolt that unlock it when the lever is pulled. As a result, the user can keep themselves lower down when working the action. The safety is a large ring at the back of the bolt, designed to be gripped and turned by a gloved finger.

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