6.5x55mm

From Wikipedia, the free encyclopedia

6.5x55mm

6.5x55mm
Type Military Rifle
Place of origin Flag of Norway Norway / Flag of Sweden Sweden
Service history
Used by Norway / Sweden
Production history
Designed 1891
Produced 1894
Specifications
Bullet diameter 6.71 mm (0.264 in)
Neck diameter 7.60 mm (0.299 in)
Shoulder diameter 11.04 mm (0.435 in)
Base diameter 12.20 mm (0.480 in)
Rim diameter 12.20 mm (0.480 in)
Rim thickness 1.50 mm (0.059 in)
Case length 55.00 mm (2.165 in)
Overall length 80.00 mm (3.150 in)
Case capacity 3.75 cm³ (58 gr H2O)
Rifling twist 220 mm (1-8.66 in)
Primer type large rifle
Maximum pressure 380 MPa (55,000 psi)
Ballistic performance
Bullet weight/type Velocity Energy
100 gr (6.5 g) HP 3,183 ft/s (970 m/s) 2,250 ft·lbf (3,050 J)
120 gr (7.8 g) BT 2,812 ft/s (857 m/s) 2,108 ft·lbf (2,858 J)
140 gr (9.1 g) SP 2,651 ft/s (808 m/s) 2,185 ft·lbf (2,962 J)
160 gr (10 g) RN 2,524 ft/s (769 m/s) 2,264 ft·lbf (3,070 J)
Source: Hodgdon [1]

6.5x55mm or 6.5x55mm SE (C.I.P.) (also known as 6.5x55mm Krag, 6.5x55mm Swedish Mauser, 6,5x55mm Mauser) is a rifle cartridge that was developed by a Norwegian-Swedish committee in 1891 for use in the new rifles then under consideration in the United Kingdom of Sweden and Norway. Norway adopted the Krag-Jørgensen, while Sweden adopted a Mauser rifle design.

Contents

[edit] Development

Early ammunition was loaded with a 10.1 grams (156 grains) long round nosed bullet (B-projectile) had a muzzle velocity of around 700 m/s (2300 ft/s), while later rounds had a 9 grams (139 grains) spitzer bullet (D-projectile) and offered a muzzle velocity up to 870 m/s (2854 ft/s).

[edit] Service

[edit] Norway

Krag-Jørgensen M1912 Carbine in 6.5x55mm
Krag-Jørgensen M1912 Carbine in 6.5x55mm

In Norwegian service, the 6.5x55mm cartridge was, in addition to be used in the Krag-Jørgensen rifles, used for the Madsen machine gun and several prototypes of self-loading rifles.

[edit] Sweden

Swedish Mauser in 6.5x55
Swedish Mauser in 6.5x55
Swedish AG-42 rifle in 6.5x55mm
Swedish AG-42 rifle in 6.5x55mm

In Swedish service the 6.5x55mm cartridge was used in both the Mauser rifle and carbine, as well as a number of machineguns and the later AG-42 semi-automatic rifle.

[edit] Sporting Use

The 6.5x55mm cartridge is highly esteemed as a game hunting round in Europe and Scandinavia, and enjoys a firm following of devotees in North America. It is used for harvesting game as large as moose in Sweden and Norway, while in Canada and the US 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 CZ, Steyr and Mauser all continue to offer sporting rifles chambered for this potent cartridge, as does the Finnish arms manufacturer SAKO/Tikka, while ammunition companies 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.[citation needed]

Expanding bullet loaded in a 6.5x55mm before and after expanding. The long base and small expanded diameter show that this is a bullet designed for deep penetration on large game. The bullet in the photo traveled more than halfway through a moose before coming to rest, performing as designed.
Expanding bullet loaded in a 6.5x55mm before and after expanding. The long base and small expanded diameter show that this is a bullet designed for deep penetration on large game. The bullet in the photo traveled more than halfway through a moose before coming to rest, performing as designed.

6.5x55mm (SKAN) is used in Sauer 200 STR (Scandinavian target rifle).

Biathlon: Before the .22LR rimfire became the standard rifle calibre for biathlon shooting under rules in 1975, the 6.5x55mm was widely used in biathlon competitions, both on account of its great inherent accuracy and its historical popularity with the Scandinavian nations who have always tended to dominate this sport.

[edit] Chamber differences

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 SE is 380 MPa (55000 PSI). SAAMI MAP for this cartridge is 46,000 CUP or 51000 PSI.[2]

[edit] See also

[edit] References

  1. ^ 6.5x55 load" data from Hodgdon
  2. ^ "6.5 x 55 Swedish Mauser data" from Accurate Powder
  • Accurate Smokeless Powders Loading Guide Number Two (Revised), Book by Accurate Arms Co, Wolfe Publishing, 2000 p. 229
  • 6.5x55mm cartridge dimensions
  • CIP CD-ROM Edition 2003