(note:use any reloading data at your own risk)
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The Ammunition
(note:use
any reloading data at your own risk)
|
The Swiss Service Cartridges
The History of the 10.4x38 Swiss Cartridge
The Model 1867/78 Vetterli Cartridge In 1867, the Swiss government adopted the blackpowder 10.4x38 cartridge for military use. Although the 10.4x38 was one of the few rimfire cartridges to be adopted for military service, it's 313gr. bullet and muzzle velocity of over 1400fps, easily marched the performance of it's contemporaries. Amongst the rifles chambered to use the 10.4x38 were the Milbank-Amsler Series of Rifles, the 1867 Peabody, and the Vetterli series of rifles. The original round had a copper-zinc case and a round nose lead bullet. However, in 1871, and again 1878, the bullet was replaced with an improved paper patched round. Despite improvements, bullet performance changed little. Then, in 1890, the Swiss replaced the blackpowder in the 1867-71/78 cartridge with a semi-smokeless powder know as P.C. 89.
Officially, the 10.4x38 cartridge was replaced in 1890 by the 7.5 Swiss GP90 cartridge. However, the 10.4x38 remained in use for many years after that. As Swiss Soldiers served, along with their issued weapon, until the age of 42, it is likely many Vetterlis remained in service well into the 20th century. Currently, no one is producing the 10.4x38 Rimfire round, except, perhaps, as a special order. However, it is possible to buy formed brass from Buffalo Arms or reshape brass for use in Vetterlis which have been converted to center-fire.
In the early 1880s, Eduard Rubin designed the first successful small-caliber copper-jacketed bullets. These were capable of withstanding velocities that well exceed those of the rounds that were in use at the time. In 1882, Rubin's cartridges competed with Hebler pattern cartridges whose core was composed of paper-mache. While the Hebler rounds were faster, the Rubin rounds proved to be more accurate. In 1884, 130 Vetterli rifles were converted to fire 7.5mm and 8mm rounds. And in 1885, the first pairing of a Rubin cartridge and Schmidt straight-pull action occurred. Over the next four years over a hundred rifles and at least 6 different rounds were tested. Finally, in 1889 a rifle and cartridge were decided upon.
The 7.5x53.5, .304 inch diameter, GP1890 was adopted along with the Schmidt-Rubin Model 1889 Rifle. The GP1890 used approximately 29 grains of a semi-smokeless powder and fired a paper patched 211gr round-nosed Steel-capped Lead bullet at approximately 1970fps. Several years later the cartridge was upgraded. It was discovered that the original primer in the GP1890 was too corrosive. Consequently, the round was redesigned with a newer, less corrosive primer. The new round was designated the GP1890/03. 
GP1890/23 (Picture courtesy of Reloader.ch) Later, in 1923, the GP1890/03 round was again modified. The new round, designated the GP1890/23 fired a 190gr CuproNickel Jacketed Lead round nose bullet and used smokeless powder. In addition, the round was lengthened to 54.5mm. The GP1890/23 generated around 37,000 psi. The GP90/23 round was available into the 1950s, and is the cartridge of choice for pre-1911 modified Schmidt-Rubins.
The biggest failing of the Schmidt-Rubin designed proved not to be the cartridge, but the action of the rifle. The inherent weakness of the design became apparent as the Swiss began experimenting with higher velocity rounds. However, by 1913 the action of the Schmidt-Rubin had been sufficiently strengthened to allow the next step in the development of the 7.5 Swiss round.
The GP11 was load with a 174 grain spitzer bullet. The round could travel at 2640 fps. The diameter of the bullet was increase, and the length of the case was increased to 55m. The GP11 generates around 45,500 psi of pressure. Most older Schmidt-Rubins were converted to fire the GP11, and the round saw service with the 1911 series, the K31 series, and the Stgw 57 series, remaining in service until the mid-1980s. Due to the greater pressures produced by the GP11 round, it is not safe to fire GP11 rounds in Model 1889 Schmidt-Rubins!!! In addition to the standard FMJ GP11 rounds, specialty rounds were produced as well. Armor-piercing Steel-cored rounds can be identified by their violet bases. These rounds can easily pierce .2" of steel plate at 550 yards. Tracer rounds burn out to 880 yards, and can be identified by their red bases. However, most Swiss match shooters use standard GP11 ammunition, a testament to the accuracy of the GP11 round. The headstamps on GP11 rounds can be read as thus; The numbers at the top and bottom of the case represents the month and year of manufacture, respectively. The letter to the left of the headstamp represents where the case was manufactured, while the letter to the right represent the finally assembly point of the cartridge. Letters used include D=Dornach, A=Altdorf, and T=Thun. As a curious side note: according to an article on Cruffler.com. The Swiss GP11 bullet strongly influenced the design of the M1 .30-06 round. For more information, click here.
Today, 7.5 ammo is finally becoming fairly easy to find. Several
companies, are now importing GP11
ammunition. GP11 ammuntion is Berdan primed, and not easily reloadable.
In addition, there are other alternatives. The first, was from INDEP of Portugal. The INDEP round is a 180gr round, traveling at
around 1950fps. INEP ammuntion is no longer available, but
Prvi Partisan is similar, and available from various sources.
Norma is the second company to produce loads the for the 7.5 Swiss round. They have a 190 gr. hollowpoint round with a velocity of 2592 fps. A 200 gr hollowpoint round with a velocity of 2493 fps. And a 180 gr soft-point round with a velocity of 2651 fps. Norma tends to be much more expensive, currently street prices range from $27 to $35, but it is also more accurate. The Norma loads offer performance similar to the 7.62 NATO round, and at least one source reports the hollowpoint round performs well as a hunting round. Finally, Ruag, the manufacturer of Swiss ammunition, also produces a line of Match grade ammunition. It is believed a lot SM Match Grade is about to be imported into the US. Imported GP11 ammunition is sold as either 480 round cases or 10 round boxes.
Each case contains eight 60 round battlepacks.
Each battle pack contains six, sealed, 10rd boxes.
As the Swiss began experimenting with a new, lighter, rifle design, they also began looking for a new, more compact, cartridge. Early in the trials period, they settle on two cartridges, one in 6.45mm, the other in 5.56mm. However, by 1981 it was determined that the 6.45mm cartridge wasn't suited for the lightweight rifles being proposed for service. Instead, a 5.6x45 cartridge, designated as the GP90, was adopted. Despite the 5.6mm designation, the Swiss round is interchangeable with NATO 5.56x45 rounds.
Unlike the current NATO which is optimized for a barrel twist of 1 in 7", the GP90 round is optimized for a 1 in 10" twist. This was done to optimize ballistic, accuracy and barrel life. The GP90 also lacks the steel core used by NATO rounds, rather it uses an lead core. The GP90 was originally clad with a nickel jacket, however, this was found to cause excessive barrel fouling, so in 1998 the nickel jackets were replaced with copper jackets. In addition, in 1999 a copper plug was added to the base of the bullet to address environmental concerns.
GP90 currently is manufactured in three variations:. the standard FMJ round, the tracer round, and a blank round. All the variation are produced by the Swiss Munitions factory, headquartered in Thun, Switzerland. However, GP90 is not normally available for private sales. GP90 Technical Data:
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