British medium-bore dangerous game cartridge. Highly effective but eclipsed by .375 H&H. Popular with ivory hunters in early 20th century.
Type: Rifle
Introduced: 1910, United Kingdom
Parent case: None
Standardization: Proprietary
Bullet diameter: 0.33" (8.38 mm)
Case length: 2.52" (64 mm)
Overall length: 3.39" (86.1 mm)
Max pressure: 50,000 PSI
Rim type: Rimless
Primer: Large Rifle
Typical twist rate: 1:12
Muzzle velocity: 2400–2700 fps
Muzzle energy: 3200–4000 ft-lbs
Effective range: 400 yd
Common bullet weights: 180, 250 gr
Primary use: Hunting
Production status: Obsolete
Also known as: .318 WR · .318 Rimless Nitro Express
History: Introduced by Westley Richards in 1910 as a medium-bore dangerous game round. Very popular with professional hunters and ivory traders from 1910-1930s. Used extensively by legendary hunter John 'Pondoro' Taylor who wrote extensively about its effectiveness. Faded after .375 H&H became the standard. The unusual .330 caliber made it somewhat proprietary.
Notable firearms: Westley Richards bolt rifles, Westley Richards Droplock double rifles, Custom Mauser actions
Similar cartridges: .333 Jeffery, 8x68mm S