11mm Pin fire
|The 10,15x61R Jarmann is probably the least known of Swedish military small arms cartridges. This cartridge was one of the most advanced and powerful of the large-caliber black powder military cartridges of its time. In its initial form the cartridge had a bottle necked case holding a 4.46 gram (68.8 grains) powder charge firing a 21.85 gram (337 grain) projectile at 474.5 meter per second (1560 feet per second). The results were an impressive trajectory and very good overall accuracy. In fact, as testing proved, a superior accuracy over that of its major military contemporaries.
The cartridge was developed for the Jarmann series of early bolt-action rifles. The rifle and cartridge was designed and developed in Norway where it was adopted and some 30,000 produced for the Norwegian military at the Kongsberg Armory. While it was superceded by the Krag-Jørgensen rifle, the Jarmann rifle remained in reserve storage until World War Two when most were destroyed by German forces. Ultimately, most of the surviving rifles were converted to either harpoon guns or to line-throwing rescue guns for civilian use. There were a variety of Norwegian cartridges for the Jarmann including commercial hunting rounds as well as blank rounds for the harpoon/line throwing gun.
The 10,15x61R was also used in three unique models of Swedish weapons. The primary use was in the Jarmann rifles produced in Sweden by the Carl Gustafs Stads Gevärsfaktori in Eskilstuna. While a number of minor test variations exist, two main production lots were manufactured in the early 1880’s. The first variation was a lot of 500 rifles that were of a single-shot design and with two-band stocks. They were distributed for testing and evaluation to Swedish Royal Life Guard (160), the Infantry Volunteer School (Infanteriets volontärskola) in Karlsborg (300) and the Swedish Infantry Shooting School (Infanteriskjutskolan) in Rosersberg (40).
An additional 1,000 rifles were produced in a second production lot reportedly for the Swedish Navy. This variation was also a bolt action but with a three-band stock and featured a controversial eight-shot tubular magazine. There was a general concern at that time regarding the safety of tubular magazines with center fire cartridges. The concern was that pointed projectiles might come in contact with the center fire primer of the cartridge ahead of it and cause a detonation. It was for this concern that many Jarmann ball cartridges have projectiles with blunt tip ogives.
The fm/1883 “3 band” Jarmann Repeating Rifle
The second Swedish weapon to use the Jarmann 10,15x61R cartridge was the kammargevär m/1884. First year production m/1867rolling block rifles were selected for conversion, which consisted of re-barreling to the Jarmann caliber and being fitted with center fire breech blocks. The converted rifles had a slightly shorter barrel and without bayonet lugs. As these rifles were intended for short-range training and practice use only, they were issued with special practice ammunition that had light charges of 0,5 to 0,7 grams of black powder and round ball projectiles. In order to accommodate the low powered practice ammunition, the barrels of the converted rifles had rifling of a much slower rifling twist rate. While a full power service cartridge could safely be fired, accuracy was severely degraded by the slower twist and was not recommended.
Archive references indicate that 1,307 kammergevär were completed for the Swedish Army. While the rifle was described as an indoor (kammar) weapon, due to the heavy smoke from firing black power cartridges, it was rarely used in that manner. Its use was more limited for smaller outdoor ranges. After limited military service the rifles were withdrawn and then made available for loan to civilian shooting organizations. In 1895 some 441 kammargevär are reported to have been placed on loan to shooting organizations and clubs such as the Frivilliga Skytteväsendet, which was later renamed the Frivilliga Skytterörelsen or FSR in 1966.
The third weapon to use the Jarmann cartridge was the kammarkarbin m/1884. Rarely known or recognized, the kammarkarbin m/1884 is a conversion of the m/1864-68 rifle to a carbine configuration. Like the kammargevär, the kammarkarbin was fitted with a new barrel chambered for the 10,15x61mm cartridge. It has the full-length fore stock and nosepiece design of the m/1870 carbine. The action, however, does not have the distinctive saddle ring and bar of the m/1870 carbine installed. The action itself is the Remington Number 1 design and especially contoured for the earlier m/1864/68 rifle conversion. The characteristic brass butt plate of the original m/1864 rifle remains with the carbine conversion. As with the kammargevär m/1884, full power ball cartridge could safely be fired, but accuracy was severely degraded by the slower twist and not recommended. Archive sources indicate that only 190 kammarkarbin were produced.
m/1884 Kammarkarbin (note brass butt plate and the absence of saddle ring and bar)
As the Jarmann rifle matured so did its cartridge. Powder charges, trajectories, and accuracy evolved during the development. While the rifles themselves may have had a limited military acceptance, the cartridges continued to be very well accepted by civilian shooters and the caliber was produced commercially in many forms. Separating the commercial from the military can be a challenge. Insofar as Swedish military service is concerned, there are two major types of ammunition for these rifles:
1. The ball service round with a paper-patched lead projectile loaded with black powder that was intended for the Jarmann rifle.
2. The second type is the reduced charge gallery round for short range shooting with the kammargevär and kammarkarbin. It is loaded with a round ball of lead and a charge of 0,5 - 0,7 gram of black powder. This ammunition was only suitable for a shooting distance of 15-30 meters.
There is also a dummy training round that was fitted with a typical unpainted wooden projectile that was characteristic of that time.
Jarmann Åren 1876-1889, Peter von Waymarn, Stockholm, 1990
The Kammargevär m/1884, https://forums.gunboards.com/showthread.php?135913-quot-1884-%E5rs-Kammargev%E4r-quot-10-15x61R-Jarmann
The Kammarkarbin m/1884, https://forums.gunboards.com/showthread.php?343691-Kammarkarbin-m-1884&highlight=kammarkarbin
Skjutbanor och Måkskjutningsmateriel för skjutöfningar med handvapen, Stockholm, 1889.
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