The Hunter Line of Standard Length Magnum Cartridges

By Kevin Madsen


I have always been interested in cartridges and ballistics. I recently purchased a program that allowed me to design cases. After conversations with Guns and Shooting Online Managing Editor Chuck Hawks, I set out to design a new cartridge. It started with the .338 caliber with the objective to develop a case that in terms of functioning and power was theoretically better than .338 Win. Mag. The result was the .338 Hunter, which can be found on the Wildcat Cartridges page at http://www.chuckhawks.com/subscribers/wildcat_cartridge_page/338_hunter.htm

Since then, I have modified the .338 Hunter in order to use .375 Ruger brass, creating the .338 Hunter-II. (See dimensions below.) Then, I used the same objectives to develop a line of cartridges based on .375 Ruger brass. Before presenting them, I will outline my ground rules:

  1. A rimless bottleneck case with a full diameter .532" rim using the current magnum bolt face standard of .532" � based on .375 Ruger Case.
  2. A neck length of 1.2 times bullet diameter or greater.
  3. A shallow versus abrupt shoulder angle (close to 20o).
  4. A case taper between that of the .375 H&H (.030 in/in) and the .375 Wby. Mag. (.008 in/in) (OD just past web - shoulder OD)/ (Length from Base to Shoulder � web thickness).
  5. Using same or shorter action to produce comparable velocities that should function well in semi-autos for reduced felt recoil.
  6. My goal was to improve on cartridge reliability and function.

I base all of the new Hunter cases on the .375 Ruger, which has the .532" rim diameter to function in a standard length action with a magnum bolt face. The full diameter rim avoids the feeding problems inherent in rebated rim designs. The shoulder angle is not at as sharp, which increases the ease of feeding the cartridge from the magazine. The long neck length provides a firmer grip on the bullet, reducing bullet movement while the cartridge is stored in a magazine, holding the bullet straighter, allowing the use of a wider assortment of bullet shapes and the bullet does not seat as far down into case.

Unlike most new cartridges, the Hunter line is not based on a radical design. Because they were conceived as hunting cartridges, they do not look like a bench rest cartridges or boast the exaggerated features that today are seen as necessary in creating a buying frenzy. They are improved in practical, rather than trendy, ways. Case capacity does not have to be the only objective in designing a case.

Conventional magnum cases require the use of long (.375 H&H length) actions and the by product of increased velocity is heavier recoil. In the Hodgdon�s 2008 Annual Reloading Manual article �Loading Cartridges for Dangerous Game� by Terry Wieland, Mr. Wieland states:

"Even increased power is relatively unimportant. The overwhelming concern is reloading ammunition for a dangerous-game rifle is absolute reliability, and that includes feeding, and ejection, as well as ignition."

Of course, Wieland did not advocate use of inadequate cartridges. He just stressed that reliably, instead of the more common maximum power and accuracy, should be the primary objective. Reliability is also very important when a second shot may be needed to harvest non-dangerous thinned skinned game, especially when few have room for missed opportunities. Terry Wieland and Chuck Hawks agree that most dangerous game is shot at close range from 50 yards or less to max of about 150 yards. Therefore, one should compare performance of dangerous-game cartridges at about 100 yards instead of at 300 yards unless one is hunting only for non-dangerous thinned skinned game outside dangerous-game territory.

The number within parentheses ( ) is case capacity in grains of water unless otherwise noted. The Hunter line is based on the .375 Ruger case.

.338 Hunter-II

  • Case capacity: 86.8 grains of water
  • Neck: ID 0.338", OD 0.369", length 0.406" (1.20 times caliber)
  • Shoulder: OD 0.500", taper 0.131/.180 = .730
  • Shoulder angle: 20 degrees
  • Web: OD 0.532", length 0.240
  • Case length: 2.5"
  • Base to shoulder: 1.914"
  • Base to neck: 2.094"
  • Case taper: (0.032/1.674) = 0.0191 inch/inch (midway between that of the .375 H&H and Wby. Mags)
  • Case wall thickness at base: 0.034" (T1)
  • Case wall thickness at shoulder: 0.017" (T2)

.338 Hunter-II compared to the .338 Win. Mag.

  • The case capacity increased by 4% or 3.2 grains over the .338 Win. Mag. (83.6)
  • Neck length is 1.2 times caliber vs. 0.98 times caliber
  • Shoulder angle is 20o vs. 25o to maximize feeding reliability
  • Case taper is 0.019 vs. 0.012

.358 Hunter

  • Case capacity: 88.1 grains of water
  • Neck: ID 0.358", OD 0.388", length 0.437" (1.22 times caliber)
  • Shoulder: OD 0.500", taper 0.112/0.153 = .730
  • Shoulder angle: 20 degrees
  • Web: OD 0.532", length 0.240
  • Case length: 2.5"
  • Base to shoulder: 1.91"
  • Base to neck: 2.063"
  • Case taper: (0.032/1.67) = 0.01902 inch/inch (midway between that of the .375 H&H and Wby. Mags)
  • Case wall thickness at base: 0.034" (T1)
  • Case wall thickness at shoulder: 0.017" (T2)

.358 Hunter compared to the .358 Norma Mag.

  • The case capacity are very close; the .358 Norma. Mag. case holds (86) just 2% or 2.1 grains less of water
  • Neck length is 1.22 times caliber vs. 0.88 times caliber
  • Shoulder angle is 20o for feeding reliability
  • Case taper is 0.019 vs. 0.0125

.375 Hunter

  • Case capacity: 89.1 grains of water
  • Neck: ID 0.375", OD 0.405", length 0.45" (1.20 times caliber)
  • Shoulder: OD 0.500", taper 0.095/0.131 = .730
  • Shoulder angle: 20 degrees
  • Web: OD 0.532", length 0.240
  • Case length: 2.5"
  • Base to shoulder: 1.919"
  • Base to neck: 2.05"
  • Case taper: (0.032/1.679) = 0.0190inch/inch (375 Ruger has 2x less taper)
  • Case wall thickness at base: 0.034" (T1)
  • Case wall thickness at shoulder: 0.017" (T2)

.375 Hunter compared to .375 Ruger

  • The case capacity 9 gr. or9 % less than the .375 Ruger (98.1 gr. Water)
  • Neck length is 1.22 times caliber vs. 0.8 times caliber
  • Shoulder angle is 20o .
  • Case taper is 0.019 vs. 0.009.Ruger has � less case taper than Hunter

.416 Hunter

  • Case capacity: 92.9 grains of water
  • Neck: ID 0.416", OD 0.444", length 0.52" (1.25 times caliber)
  • Shoulder: OD 0.505", taper 0.061/0.084 = .730
  • Shoulder angle: 20 degrees
  • Web: OD 0.532", length 0.240
  • Case length: 2.5"
  • Base to shoulder: 1.896"
  • Base to neck: 1.98"
  • Case taper: (0.027/1.656) = 0.016 inch/inch
  • Case wall thickness at base: 0.034" (T1)
  • Case wall thickness at shoulder: 0.017" (T2)

.416 Hunter compared to 416 Rem. Mag.

  • Case capacity: 8.3 grains less or 8% less (101.2)
  • Neck length 1.25 diameters versus 1
  • Case taper 0.016 versus 0.012
  • Shorter action, Standard mag. action versus magnum action

.458 Hunter

  • Case capacity: 96.9 grains of water
  • Neck: ID 0.458", OD 0.481", length 0.573" (1.25 times caliber)
  • Shoulder: OD 0.505", taper 0.024/0.033 = .730
  • Shoulder angle: 20 degrees
  • Web: OD 0.532", length 0.240
  • Case length: 2.5"
  • Base to shoulder: 1.894"
  • Base to neck: 1.927"
  • Case taper: (0.027/1.654) = 0.0163 inch/inch
  • Case wall thickness at base: 0.034" (T1)
  • Case wall thickness at shoulder: 0.017" (T2)

.458 Hunter versus 458 Win Mag.

  • The case capacity are very close; the Hunter case holds just 4% or 3.9grains more
  • Neck length is 1.22 times caliber vs. 0.88 times caliber
  • Shoulder angle is 20o for feeding reliability
  • Case taper is 0.019 vs. 0.0125



Back to Wildcat Cartridges

Copyright 2009 by Kevin Madsen and/or chuckhawks.com. All rights reserved.


HOME / GUNS & SHOOTING / NAVAL, AVIATION & MILITARY / TRAVEL & FISHING / MOTORCYCLES & RIDING / ASTRONOMY & PHOTOGRAPHY / AUDIO