.338 Winchester Magnum

.338 Winchester Magnum
.375 H&H Magnum (Left) .338 Winchester Magnum (Right) US Quarter for scale
TypeRifle
Place of originUSA
Production history
ManufacturerWinchester Repeating Arms
Produced1958
Specifications
Parent case.375 H&H Magnum
Case typeBelted, bottleneck
Bullet diameter.338 in (8.6 mm)
Neck diameter.369 in (9.4 mm)
Shoulder diameter.491 in (12.5 mm)
Base diameter.513 in (13.0 mm)
Rim diameter.532 in (13.5 mm)
Rim thickness.050 in (1.3 mm)
Case length2.500 in (63.5 mm)
Overall length3.340 in (84.8 mm)
Case capacity86 gr H2O (5.6 cm3)
Rifling twist1-10"
Primer typeLarge rifle magnum
Maximum pressure64,000 psi
Ballistic performance
Bullet mass/type Velocity Energy
200 gr (13 g) SP 2,950 ft/s (900 m/s) 3,866 ft⋅lbf (5,242 J)
225 gr (15 g) SP 2,800 ft/s (850 m/s) 3,918 ft⋅lbf (5,312 J)
250 gr (16 g) SP 2,655 ft/s (809 m/s) 3,914 ft⋅lbf (5,307 J)
275 gr (18 g) SP 2,489 ft/s (759 m/s) 3,784 ft⋅lbf (5,130 J)
Test barrel length: 24
Source(s): Accurate Powder[1]

The .338 Winchester Magnum is a .338 in (8.6 mm) caliber, belted, rimless, bottlenecked cartridge introduced in 1958 by Winchester Repeating Arms. It is based on the blown-out, shortened .375 H&H Magnum.[2] The .338 in (8.6 mm) is the caliber at which medium-bore cartridges are considered to begin. The .338 Winchester Magnum is the first choice among professional brown bear (specifically grizzly bear) guides in Alaska to back up clients where a powerful stopping caliber is required on charging bears.[3] It is also the most popular medium-bore cartridge in North America[4] and has the most widely available choice in rifles among medium bore rifles. The action length is the same as a .30-06, and most major rifle manufacturers in the United States chamber rifles for the cartridge including the semi-automatic Browning BAR Mk II Safari, making it a very powerful combination against charging dangerous game.[5][6] The cartridge was intended for larger North American big-game species and has found use as for the hunting of thin-skinned African plains-game species.[1]

  1. ^ a b "Western Powders Reloading and Load Guide" (PDF) (6.0 ed.). Accurate Powder. p. 59. Retrieved 2017-09-04.
  2. ^ Mushial, Gregory J (1998-11-09). "338 Winchester Magnum". GMDR.com. Retrieved 2017-09-04.
  3. ^ Hawks, Chuck. "Firearms for Defense against Bears". Retrieved 2017-09-04.
  4. ^ "338 Winchester Magnum". Norma Precision AB. Retrieved 2 June 2011.
  5. ^ "Chuck Hawks 338 Win Mag". Retrieved 2014-03-25.
  6. ^ "Rifles Dangerous Game". Retrieved 2014-03-25.