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6.5x52mm Mannlicher-Carcano
Type	Rifle
Place of origin	Kingdom of Italy
Service history
In service	1891-1970
Used by	Italy, Finland, Nazi Germany
Wars	First Italo-Ethiopian War, Italo-Turkish War, World War I, Second Italo-Abyssinian War, Spanish Civil War, World War II
Production history
Designed	1889-1891
Produced	1891-Present
Specifications
Case type	Rimless, bottleneck
Bullet diameter	6.81 mm (0.268 in)
Neck diameter	7.52 mm (0.296 in)
Shoulder diameter	10.85 mm (0.427 in)
Base diameter	11.42 mm (0.450 in)
Rim diameter	11.42 mm (0.450 in)
Case length	52.5 mm (2.07 in)
Ballistic performance
Bullet weight/type	Velocity	Energy
10.5 g (162 gr) RN	700 m/s (2,300 ft/s)	2,572 J (1,897 ft·lbf)
10.5 g (162 gr) RN	661 m/s (2,170 ft/s)	2,293 J (1,691 ft·lbf)
Test barrel length: above 780 mm; below 445 mm.

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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.

[edit] Design

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^{[citation needed]}, 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.)

[edit] Performance

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.^{[citation needed]} This characteristic is due to the high sectional density of the round (the extreme bullet length compared to its diameter) and probably^[vague] 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).^{[citation needed]}

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.^{[citation needed]}

A 6.5x52 Carcano cartridge loaded with a modern hunting bullet.

[edit] Notable uses

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.

[edit] See also

• List of rifle cartridges
• 6 mm caliber

[edit] References

• 6.5x52mm Carcano cartridge dimensions
• www.il91.it
• G.Simone, R. Belogi, A. Grimaldi, "Il 91", Ravizza (1970)