.505 Gibbs

.505 Gibbs

Type Rifle
Place of origin England
Production history
Designer George Gibbs
Designed 1910
Manufacturer Gibbs
Produced 1911
Specifications
Parent case none
Case type Rimless, Bottleneck
Bullet diameter .505 in (12.8 mm)
Neck diameter .538 in (13.7 mm)
Shoulder diameter .600 in (15.2 mm)
Base diameter .640 in (16.3 mm)
Rim diameter .640 in (16.3 mm)
Rim thickness .065 in (1.7 mm)
Case length 3.150 in (80.0 mm)
Overall length 3.850 in (97.8 mm)
Case capacity 178 gr H2O (11.5 cm3)
Rifling twist 1 in 16 (406 mm)
Primer type .254/Kynoch#40/Large Rifle
Maximum pressure 39,160 psi (270.0 MPa)
Ballistic performance
Bullet weight/type Velocity Energy
600 gr (39 g) Protected Point 2,100 ft/s (640 m/s) 5,877 ft·lbf (7,968 J)
600 gr (39 g) FMJ 2,100 ft/s (640 m/s) 5,877 ft·lbf (7,968 J)
525 gr (34 g) Welded Core SP 2,300 ft/s (700 m/s) 6,180 ft·lbf (8,380 J)
Test barrel length: 24"
Source(s): Norma [1] & MidwayUSA [2]

The .505 Gibbs cartridge was designed by George Gibbs in 1911. The cartridge was originally known as the .505 Rimless Nitro Express or simply as the .505 Rimless. C.I.P. refers to the cartridge as the 505 Mag. Gibbs in their publications. It is a .50 caliber (12.8 mm) rimless bottlenecked cartridge intended for magazine-fed rifles.

General information

The .505 Gibbs has a case capacity of 178 grains (11.5 g) of water.[3] This cartridge was originally loaded with 90-grain (5.8 g) of cordite and 525-grain (34.0 g) bullet at 2,300 ft/s (700 m/s) for 6,166 ft·lbf (8,360 J) of kinetic energy.[3] While the .505 Gibbs has a greater case capacity than most modern cartridges, it is loaded to lower pressures.[3] The C.I.P. recommends a pressure standard of 2,700 bars (39,160 p.s.i.) for the cartridge.[4] As .505 Gibbs was intended for hunting dangerous game in a tropical environment and due to the temperature sensitivity of cordite the lower pressures provided a greater safety and reliability margin.

The .505 Gibbs has a unique bullet diameter of .505 in (12.8 mm) while most other .50 caliber bullets have diameters of .510 in (13.0 mm). Barnes Bullets and Woodleigh Bullets are a few of the bullet manufacturers who produce component bullets for reloading in this caliber. Woodleigh Bullets does not recommend impact velocities of over 2,250 ft/s (690 m/s) for their .505 caliber 525 gr. Weldcore bullets.[5]

Premium dangerous game rifle manufacturers, such as Hartmann & Weiss and Westley Richards build expensive but thoroughly reliable .505 Gibbs rifles on Mauser 98 actions. Ceska Zbrojovka (CZ) currently manufactures the Safari Classics rifle[6] for this cartridge. Doumoulin Herstal SA of Belgium offers the cartridge in their White Hunter model.[7] Modern semi-automatic rifles are also available in this cartridge from Vigilance Rifles.[8]

As of 2013, Norma, Nosler and Kynoch are offering loaded ammunition in .505 Gibbs. Bullets are available from Barnes, Cutting Edge Bullets, Woodleigh Bullets, and North Fork Bullets.

Design and specifications

The .505 Gibbs is one of the most voluminous cases designed. The large volume was required as the cartridge was designed to burn cordite as its propellant. CIP has published specifications for the cartridge.

CIP compliant schematic of the .505 Magnum Gibbs

The CIP requires that a barrel have 5 grooves, twist rate of a bore Ø of one revolution in 406 mm (16.0 in), a bore Ø of 12.55 mm (0.494 in) and a groove Ø of 12.80 mm (0.504 in) with each grove measuring 5.33 mm (0.210 in) wide. The recommended pressure for the .505 Gibbs is 2,700 bar (39,000 psi).

Sporting use

The .505 Gibbs is a niche cartridge, designed for hunting heavy, dangerous game, such as elephant, cape buffalo and grizzly bear.

In literature

The cartridge's claim to fame was its use by the fictional character, Robert Wilson, the hunter of Ernest Hemingway's short story The Short Happy Life of Francis Macomber.

See also

References

  1. ↑ Norma Ammunition
  2. ↑ MidwayUSA
  3. 1 2 3 http://www.huntnetwork.net/modules/wfsection/html/505magnum.pdf
  4. ↑ CIP
  5. ↑ "Bullet Specifications, Dimensions & Details". Woodleigh Bullets. Archived from the original on 3 July 2010. Retrieved 12 August 2010.
  6. ↑ http://cz-usa.com/products/by-brand/safari-classics/
  7. ↑ "White Hunter". dumoulin-herstal.com. Dumoulin Herstal. 2004. Retrieved 9 December 2010.
  8. ↑ 50 BMG SEMI AUTOMATIC RIFLES

External links

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