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Krag–Jørgensen

Krag–Jørgensen is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Krag–Jørgensen rather than just read about it. In short: The Krag–Jørgensen is a repeating bolt-action rifle designed by the Norwegians Ole Herman Johannes Krag and Erik Jørgensen in the late 19th century. It was adopted as a standard arm by Norway, Denmark, and the United States.

Krag–Jørgensen — main illustration
Krag–Jørgensen — illustration

Key takeaways

  • Krag–Jørgensen belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Krag–Jørgensen to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Krag–Jørgensen from memory before moving on to harder problems.

Reference excerpt

The Krag–Jørgensen is a repeating bolt-action rifle designed by the Norwegians Ole Herman Johannes Krag and Erik Jørgensen in the late 19th century. It was adopted as a standard arm by Norway, Denmark, and the United States. About 300 were delivered to Boer forces of the South African Republic. A distinctive feature of the Krag–Jørgensen action is its magazine. While many other rifles of its era use an integral box magazine loaded by a charger or stripper clip, the magazine of the Krag–Jørgensen is integral with the receiver (the part of the rifle that houses the operating parts), featuring an opening on the right hand side with a hinged cover. Instead of a charger, single cartridges are inserted through the side opening, and are pushed up, around, and into the action by a spring follower. Later, similar to a charger, a claw type clip would be made for the Krag that allowed the magazine to be loaded all at once, also known as the Krag "speedloader magazine". The design presents both advantages and disadvantages compared with a top-loading "box" magazine. Normal loading was one cartridge at a time, and this could be done more easily with a Krag than a rifle with a "box" magazine. In fact, several cartridges can be dumped into the opened magazine of a Krag at once with no need for careful placement, and when shutting the magazine-door the cartridges are forced to line up correctly inside the magazine. The design was also easy to "top off", and unlike most top-loading magazines, the Krag–Jørgensen's magazine could be topped up without opening the rifle's bolt. The Krag–Jørgensen is a popular rifle among collectors, and is valued by shooters for its smooth action.

Early development

The 1880s were the decade where smokeless powder came into general use, and the calibre of various service rifles diminished as new small-bore, high-velocity cartridges using smokeless propellant were developed. Many nations adopted repeating bolt-action rifles using such cartridges during this decade. Even though Norway had adopted the repeating Jarmann rifle in 1884, it was soon clear that it was at best an interim weapon. Ole Krag, captain in the Norwegian Army and director of Kongsberg Våpenfabrikk (the government weapons factory), therefore continued the development of small arms, as he had since at least 1866. Not satisfied with the tubular magazine of the Jarmann rifle and his earlier Krag–Petersson rifle (adopted by the Royal Norwegian Navy in 1876), he enlisted the help of master gunsmith Erik Jørgensen. Together, they developed the capsule magazine. The principal feature of the capsule magazine was that instead of being a straight box protruding below the stock of the rifle, it wrapped around the bolt action. Early models contained ten rounds and were fitted to modified versions of the Jarmann—though they could be adapted to any bolt-action rifle.

In 1886, Denmark was on the verge of adopting a new rifle for its armed forces. One of the early prototypes of the new rifle was sent to Denmark. The feedback given by the Danes was vital in the further development of the weapon. The test performed in Denmark revealed the need to lighten the rifle, as well as the possible benefits of a completely new action. Krag and Jørgensen therefore decided to convert the magazine into what they referred to as a half-capsule, containing only five rounds of ammunition instead of the previous ten. They also, over the next several months, combined what they considered the best ideas from other gunsmiths with a number of their own ideas to design a distinct bolt action for their rifle. The long extractor, situated on top of the bolt, was inspired by the Jarmann mechanism, while the use of curved surfaces for cocking and ejecting the spent round was probably inspired by the designs from Mauser. For a time after the weapon was adopted by Denmark they experimented with dual frontal locking lugs, but decided against it on grounds of cost and weight. The ammunition of the day did not need dual frontal locking lugs, and the bolt already had three lugs—one in front, one just in front of the bolt handle, and the bolt handle itself—which were considered more than strong enough. The rifle had a feature known as a magazine cut-off. This is a switch on the left rear of the receiver. When flipped up (on the Norwegian Krag-J rifles and carbines), the cut-off does not allow cartridges in the internal magazine to be fed into the chamber by the advancing bolt. This was intended to be used for when soldiers were comfortably firing at distant targets. After each shot, the soldier would take a round out of his pouch and load it directly into the chamber as if he was using single-shot rifle. The rounds in the magazine are thus held in reserve. If the enemy suddenly charged or the soldier was ordered to charge, the soldier could then retract the cut-off for up to five rounds of rapid shooting. The M1903 Springfield that replaced the Krags had a magazine cutoff, as did the SMLE (Lee–Enfield) until 1915.

Danish Krag–Jørgensen rifles

After strenuous tests, Denmark adopted the Krag–Jørgensen rifle on July 3, 1889. The Danish rifle differed in several key areas from the weapons later adopted by the United States and Norway, particularly in its use of a forward (as opposed to downward) hinged magazine door, the use of rimmed ammunition, and the use of an outer steel liner for the barrel. The Danish Krag–Jørgensen was chambered for the 8×58R cartridge (0.31 in / 7.87 mm), and was at least in the early years used as a single shooter with the magazine in reserve. It stayed in service right up to the German invasion of Denmark on April 9, 1940. Danish Krags were given the German identification code Scharfschützen-Gewehr 312(d).

Subtypes of the Danish Krag–Jørgensen While information on the various subtypes of the Krag–Jørgensen used in Denmark has proven difficult to find, at least the following subtypes were manufactured:

… excerpt ends here. Continue reading the full article.

Illustrations

Krag–Jørgensen illustration
Krag–Jørgensen: Technical drawing of an early Krag–Jørgensen
Technical drawing of an early Krag–Jørgensen
Krag–Jørgensen: Closeup of the Krag–Jørgensen receiver and magazine door on a Norwegian M1912 carbine
Closeup of the Krag–Jørgensen receiver and magazine door on a Norwegian M1912 carbine
Krag–Jørgensen: Close-up of an open American 1898 Springfield Krag magazine loading gate
Close-up of an open American 1898 Springfield Krag magazine loading gate
Krag–Jørgensen: Danish M1889 Krag–Jørgensen carbines (8×58 mmR), from the collections of the Swedish Army Museum, Stockholm.
Danish M1889 Krag–Jørgensen carbines (8×58 mmR), from the collections of the Swedish Army Museum, Stockholm.

Worked examples

Example 1 — a first encounter with Krag–Jørgensen

Start with the simplest possible case. Write down what Krag–Jørgensen claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Krag–Jørgensen before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Krag–Jørgensen ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Krag–Jørgensen

In research
Krag–Jørgensen appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Krag–Jørgensen in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Krag–Jørgensen is common in secondary-school and first-year university syllabi. It links to neighbouring topics 6.5×55mm rifles, Bolt-action rifles of Norway, Early rifles, so understanding it makes those chapters shorter.
In everyday life
Look for Krag–Jørgensen outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Krag–Jørgensen in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Krag–Jørgensen means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Krag–Jørgensen out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Krag–Jørgensen in simple terms?

The Krag–Jørgensen is a repeating bolt-action rifle designed by the Norwegians Ole Herman Johannes Krag and Erik Jørgensen in the late 19th century. It was adopted as a standard arm by Norway, Denmark, and the United States.

Why does Krag–Jørgensen matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Krag–Jørgensen?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Krag–Jørgensen.

Tags

  • 6.5×55mm rifles
  • Bolt-action rifles of Norway
  • Early rifles
  • Norwegian inventions
  • Rifles of the Cold War
  • Rifles of the United States
  • Rotary magazine firearms
  • Weapons and ammunition introduced in 1886
  • World War II military equipment of Denmark
  • World War II military equipment of Norway
  • World War II rifles

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