|This article needs additional citations for verification. (January 2013)|
|Place of origin||USA|
|Designer||Col. Townsend Whelen / James Howe|
|Case type||Rimless, bottleneck|
|Bullet diameter||.358 in (Script error mm)|
|Neck diameter||.385 in (Script error mm)|
|Shoulder diameter||.441 in (Script error mm)|
|Base diameter||.472 in (Script error mm)|
|Rim diameter||.473 in (Script error mm)|
|Case length||2.494 in (Script error mm)|
|Overall length||3.340 in (Script error mm)|
|Primer type||Large rifle|
|180 gr (Script error g) FN||2,963 ft/s (Script error m/s)||3,510 ft·lbf (Script error J)|
|200 gr (Script error g) SP||2,798 ft/s (Script error m/s)||3,478 ft·lbf (Script error J)|
|225 gr (Script error g) SBT||2,613 ft/s (Script error m/s)||3,412 ft·lbf (Script error J)|
|250 gr (Script error g) RN||2,523 ft/s (Script error m/s)||3,535 ft·lbf (Script error J)|
| Test barrel length: 24|
Source(s): Accurate Powder 
The .35 Whelen is a powerful medium-bore rifle cartridge that does not require a magnum action or a magnum bolt-face. The parent of this cartridge is the .30-06 Springfield, which is necked-up to accept a bullet diameter of .358 in (Script error mm). This cartridge is more powerful than its parent, especially in killing power on large game.
The .35 Whelen was originally developed in 1922 as a wildcat cartridge by Col. Townsend Whelen, and built by gunsmith James V. Howe (later of Griffin & Howe). At the time Colonel Townsend Whelen was the commanding officer of the Frankford Arsenal, and James V. Howe was a toolmaker in the same establishment.
The 1923 issue of American Rifleman Colonel Whelen referred to it as "the first cartridge that I designed" and in that same article stated that, "Mr. James V. Howe undertook this work of making dies, reamers, chambering tools, and of chambering the rifles, all in accordance with my design."
Suitable .358 in (Script error mm) bullets range in weight from 150 to 300 grains (Expression error: Unrecognised punctuation character "[". to Expression error: Unrecognised punctuation character "[". g). This round can use .38/.357 pistol bullets for cheap practice, low recoil target shooting, and varmint hunting. Using a 250-grain (Script error g) bullet, the .35 Whelen will generate 3,500 ft·lbf (Script error J) at the muzzle from a 24 in (Script error cm) barrel.
The .35 Whelen is the ballistic twin of the .350 Remington Magnum. With the correct bullet choice this cartridge is suitable for virtually all thin-skinned large and dangerous game. The European designation for this cartridge would be 9 x 63 mm; with its wide bullet selection and high muzzle energy it is in the same echelon as the venerable 9.3x62mm.