It could be that what you have is a .35 Winchester, a round introduced in 1903 for the Model 95 Winchester lever action. The .35 Whelen was an attempt to create a rimless version of the .35 Winchester.

Dimensions:
Case length 2.415
Loaded length 3.16
Head diameter .461
Rim Diameter .543
Neck diameter .383
Shoulder diameter .428
Case capacity (grains of water) 68.74

This compares with the case capacity of the 9X57R (62.22); .35 Whelen (72.63); .400/.350 (78.73).

Factory load for the .35 Winchester: 250 grain bullet at 2195 fps at 45,000 psi.

50 grains of 3031 produces 2300 fps with a 250 grain bullet in the .400/.350.

Shot in a Farquharson, the .35 Winchester should match the performance of the .400/.350.

Cases can be formed from .405 Winchester brass.