6.5x55mm or 6.5x55mm SE (C.I.P.) (also known as 6.5x55mm Krag, 6.5x55mm Swedish Mauser or 6,5x55mm Mauser) is a rifle cartridge developed in 1891 for use in the new rifles then under consideration by the Swedish-Norwegian Kingdom. The two nations had independent armies and the normal procedure at that time was for the respective governments to use the same ammunition and then purchase small arms of their choice. Norway adopted the Krag-Jørgensen rifle, while Sweden adopted a Mauser rifle design. The cartridge has a smaller bullet diameter and lower recoil than other full-power rifle cartridges, but a longer case length than any intermediate-power cartridge, and pre-dates other intermediate cartridges by fifty years; it is therefore difficult to classify as one or the other.
Early ammunition was loaded with a 10.1 gram (156 grain) long round-nosed bullet (B-projectile) with a muzzle velocity of 700 m/s (2300 ft/s), while later rounds (from 1941 onwards) used a 9.1 gram (140 grain) spitzer bullet (D-projectile) with a muzzle velocity of 800 m/s (2625 ft/s).
The 6.5x55mm cartridge is highly esteemed as a hunting round in Europe, Scandinavia, and North America. It is used for harvesting most kind of game including elk, moose and brown bear in Sweden and Norway, while in Canada and the United States it is used for taking deer and other medium-sized game. Sportsmen who favor the round laud the combination of low recoil coupled with the cartridge's inherent accuracy and superb penetrative qualities.
European rifle makers including Sauer, CZ, Steyr and Mauser offer sporting rifles chambered for this cartridge, as does the Finnish arms manufacturer SAKO/Tikka, while ammunition manufacturers such as Norma, Lapua and Hornady offer loadings of the 6.5x55mm round that are designed for use only in modern hunting rifles that can tolerate higher chamber pressures. These modern loadings should never be used in older military rifles.
The cartridge is also used in the Sauer 200 STR (Scandinavian Target Rifle).
The 6.5x55mm cartridge was widely used in biathlon competition until 1975 (when it was replaced by the .22 Long Rifle (.22 LR) rimfire cartridge), because of its inherent accuracy and historical popularity with the Scandinavian nations who have dominated this sport.
Due to different interpretations of the standard, i.e. the standards of manufacturing using maximum chamber in the Krag vs. minimum chamber in the Swedish Mauser, a small percentage of the ammunition produced in Norway required a heavy push on the bolt handle to chamber in the Swedish gun. After the rumor of this difference first surfaced in 1900, it was examined by the Swedish military. They declared the difference to be insignificant, and that both the Swedish and Norwegian ammunition was within the specified parameters laid down. Despite this finding, the Swedish weapon-historian Josef Alm repeated the rumor in a book in the 1930s, leading many to believe that there was a significant difference. The CIP MAP for the 6.5 x 55 is 380 MPa (55000 PSI). SAAMI MAP for this cartridge is 46,000 CUP or 51000 PSI.
cs:6,5 x 55 mm Mauser de:6,5 x 55 mm Mauser fr:6,5 mm Mauser no:6,5 x 55 mm ru:6,5×55 мм sv:Kaliber 6,5 x 55 mm
The 6.5x50mm Semi-Rimmed Japanese cartridge was adopted by the Imperial Japanese Army in 1897 along with the Type 30 Arisaka Infantry Rifle and Carbine. The new rifle and cartridge replaced the 8x52mm Murata round used in the Type 22 Murata Rifle. In 1902 the Imperial Japanese Navy chambered its Type 35 Rifle for the cartridge as well. In 1905, the round also came to be offered in the Type 38 Arisaka Infantry Rifle and Carbine, both of which obsoleted the Type 30 in Imperial Army service. Type 44 Cavalry Carbines, first adopted in 1911, were also chambered in 6.5x50mm.
Early 6.5x50mm cartridges had a cupro-nickel round nosed bullet weighing fired with approximately of smokeless powder. This was later changed with the adoption of the Type 38 when Japan, in line with the other great powers around the same time, changed to the pointed or spitzer bullet in the first decade of the twentieth century. The Type 38 spitzer-bullet round fired a bullet with a powder charge of for a muzzle velocity of around .
The Type 38 spitzer version of the 6.5x50mm cartridge remained unchanged until after the adoption of the Type 11 Light Machine Gun in 1922. The Type 11 was initial meant to fire standard Type 38 Rifle ball ammunition by means of ordinary five-shot Type 38 stripper clips. Subsequent use indicated that the higher pressures generated by the standard rifle ammunition caused parts wear and breakage in machine guns. It was thus decided to reduce the powder charge of Type 11 6.5 mm ammunition to overcome the problem. This reduced charge 6.5 mm ammunition can be identified by a letter "G" in a circle stamped on the outside of the ammunition packaging which stands for the first letter of genso - the Japanese word for "reduced." This special ammunition was also issued to soldiers carrying the Type 96 Light Machine Gun introduced in 1936 and to snipers issued the Type 97 Sniper Rifle, introduced in 1937. The advantage of the reduced charge ammunition to the sniper was it aided in his concealment as the reduced charge rounds produced less muzzle flash than standard rounds and thus did not give away the sniper's position.
6.5 gallery ammunition incorporated a paper or wood bullet and dummy rounds as issued to Japanese forces were either all brass rounds or were more commonly red varnished wood with a metal base and rim. Ammunition used in the spigot-type Japanese grenade launchers often have paper bullets and can be identified by staked primers.
Other 6.5x50mm long-arms used by Japan included a few Type 13 Mauser rifles produced at Hoten (Mukden) Arsenal in Manchuria, China. These rifles were built on Danish Nielsen-Winther machinery originally for Manchurian warlord Chang Tso Lin beginning in 1924. After Japan took over the arsenal after the Manchurian Incident of 1931 the Type 13 rifle continued to be produced in 7.92x57mm Mauser caliber, but an unknown number were also built in 6.5x50mm. The Type I rifles built by Italy for Japan under the terms of the Anti-Comintern pact from 1939-1943 are in standard 6.5x50 mm Japanese. Their Italian origin should not be taken to mean that these will safely fire the longer, but outwardly similar, 6.5x52mm Carcano round. An unknown number of Dutch M1895 Mannlicher rifles and carbines captured by Japanese forces during the seizure of the Dutch East Indies in 1942 were converted to 6.5x50mm from 6.5x53mm Dutch rimmed caliber.
After observing the effectiveness of the Type 30 6.5x50mm round as used against them during the Russo-Japanese War of 1904-1905, leading Russian arms designers chambered early Russian semi-automatic rifle designs for the Japanese round. Since the standard Russian military rifle cartridge of the time, the 7.62x54R rimmed round, was too powerful and generated excessive recoil in an automatic arm - a 6.5 mm round was seen as more appropriate. Early semi-automatic designs by Vladimir Fedorov utilized 6.5x50 mm including the Fedorov Avtomat rifle which was actually issued to troops, though in small numbers. Later, Russian troops on the Armenian front were issued with Type 38 Carbines given by the Tsar's government. Russians also tended to modify the Type 38s magazine latch, as it was found that gloved hands would sometimes inadvertently nudge the magazine release and dump the ammunition.
In 1914 approximately 150,000 Arisaka Type 30 and Type 38 Rifles and Carbines were sold to British forces - mainly the Royal Navy, where they were used for training. The 6.5x50mm round was subsequently produced in Britain by the Kynoch company and was officially adopted for British service as the caliber Mk II in 1917. The Arab armies organized by British Captain T. E. Lawrence to fight against the Ottoman Empire during World War I are purported to have been issued with Type 30 Rifles by the British in 6.5 mm though some have opined that the Bedouin forces mainly used captured Ottoman Mausers instead. In all, the 6.5x50 mm Japanese semi-rimmed round has been used in either Japanese or domestically designed weapons by Japan, Russia, the United Kingdom, China, North Korea, South Korea, Thailand, Finland and Indonesia. Many of the British Naval Arisakas were given to the White Russians.
The Russians, having a surplus of Type 30 and Type 38 rifles from both direct purchase from Japan during WWI and also having captured examples during the Russo-Japanese War, had warehoused some of these rifles in Finland. During the Russian Revolution, many Finns seized the chance for independence and took many Arisakas from Russian arsenals. They were used mainly by Finn cavalry and after Finland's independence, experiments were taken to upgrade the Type 38s to 7.92 Mauser. With parts and ammunition drying up, Finland relegated the Arisaka to the reserves and the merchant marines before trading a large number of them off to Estonia. Finn used Arisakas will have district numbers and an 'S' branded on the stock.
The cartridge was only available in loaded form to shooters in the United States by Norma of Sweden for many years but now brass cases can be had from Graf & Sons and quality hand-loads made up. Kinematics Research of Tennessee also loads this cartridge, as does Hornady. Bullets are standard .264 caliber.
es:6,5 x 50 Arisaka ja:三十年式実包 no:6,5 x 50 mm Arisaka pl:Nabój 6,5 x 50 mm SR ru:6,5×50 мм Арисака zh:6.5mm有坂
6.5x52mm Carcano or 6.5x52mm Mannlicher-Carcano is an Italian military 6.77 mm (.266/67 cal.) rimless bottle-necked rifle cartridge, developed from 1889-1891 and used in the Carcano 1891 rifle and many of its successors. A common synonym in US gun literature is "6.5mm Italian". In US parlance, "Carcano" is frequently added to better distinguish it from the rimmed hunting cartridge 6.5x52mmR (US version: .25-35 Winchester). Ballistically, its performance is very similar to that of the 6.5x54mm Mannlicher-Schönauer.
Under the direction of the "Commissione delle Armi Portatili" (Commission for Portable Weapons), instituted in 1888 to develop a smokeless-powder rifle for the Italian Army, the "Reale Laboratorio Pirotecnico di Bologna" (Royal Pyrotechnical Laboratory of Bologna) developed and tried several different cartridge designs, with a bullet diameter from 8 mm to 6 mm. Finally, due also to the influence of Maj. Antonio Benedetti, of the Brescia Arsenal, Secretary of the Commission and strong supporter of the advantages of smallbore cartridges, the 6.5x52 cartridge was definitively adopted in March 1890, prior to the adoption of the rifle that used it (the Model 1891 Carcano rifle).
After the adoption of the cartridge, the arsenals technicians worried about the characteristics of the original ballistite load, since that propellant was considered too erosive (flame temperature of 3000-3500 °C) and not stable under severe climatic conditions. Several other loads were tested, including the British cordite but without good results, until the Reale Polverificio del Liri (Royal Explosives Factory of Liri) developed a new propellant called "Solenite", composed of trinitrocellulose (40%), dinitrocellulose (21%), nitroglycerine (36%), mineral oil (3%), and shaped in large tube-like grains. The new propellant, that reduced the flame temperature to 2600 °C and proved to be very stable, was adopted in 1896 and never changed until the end of the military production of the cartridge.
The 6.5x52mm Carcano was designed as a full-blown infantry cartridge. In accordance with the tactics of the time, the adjustable rear sight of the rifle allowing for volley fire up to 2,000 metres. 6.5x52mm Carcano was the first to be officially adopted of a class of similar smallbore military rifle cartridges which included the 6.5x50 Arisaka (Japan), 6.5x53R Mannlicher (Romania / Netherlands), 6.5x54 Mannlicher-Schönauer (Greece), 6.5x55 Swedish Mauser (also Norwegian Krag-Jørgensen), 6.5x58 Portuguese.
A comparison with larger bore smokeless powder cartridges of the 7.62mm and 8mm calibre class (which class started in 1886 with the French 8x50R Lebel, continuing with the German 7.92x57, the Austrian 8x50R, the British .303, the Russian 7.62x54R, the Belgian and Argentine 7.65x53, the .30-40 Krag, and the much later .30-03 and .30-06) may make the 6.5mm rounds appear "underpowered" on paper though, and lacking in stopping power. On the other hand, the small bore cartridges seem to have a long list of advantages, as flatness of trajectory, outstanding penetration at distance, less weight, less recoil, smaller dimensions, and less material required in production.
Its short-lived intended successor cartridge, the 7.35x51mm Carcano, is sometimes identified as the first intermediate round, before the German 7.92x33 and the Soviet 7.62x39.
The original 6.5x52mm barrel design, developed by the Brescia Arsenal at the same time as the cartridge before development of the M91 Carcano Rifle itself, used a gain twist barrel with deep rifling to reduce wear, extend barrel life and give consistent accuracy. Gain twist has a slow initial twist in the barrel progressively getting faster until the final twist rate is attained near the muzzle, resulting in less torque being imparted to the bullet during the highest stress phase of the interior ballistic cycle, and thus less barrel wear in the throat of the barrel. (Gain twist was phased out in the last production of the Carcano rifle in favor of conventional rifling.)
The 6.5x52 Carcano is an effective deer cartridge up to 200 m (220 yards), with properly-bulleted ammunition. Its main drawback in military use was that the standard Italian service round had a round-nosed bullet and was highly stable (did not usually tumble unless it hit bone), giving many narrow-channel straight-through wounds. This characteristic is due to the high sectional density of the round (the extreme bullet length compared to its diameter) and probably accounts for the second shot that fatally wounded President John F. Kennedy and seriously wounded Governor John Connally and was later allegedly found in pristine condition on a stretcher outside an operating room in Parkland Memorial Hospital (located at 5201 Harry Hines Boulevard, just west of Oak Lawn in Dallas, Texas (USA).
Hand loaders should note that the currently available factory ammunition may lack accuracy due to use of a 6.7 mm (.264 in) bullet instead of the 6.8 (.268 in) as originally loaded.
The cartridge achieved some notoriety as having been the choice of Lee Harvey Oswald, who used a World War II Italian Carcano rifle in this chambering to assassinate President John F. Kennedy.