Whatever happened to .280 Ross?

[Nolo]

It seems like an ideal cartridge for long rifles, why did it die out?

 

[Hypnogator]

why did it die out?

Tainted by the name Ross.

The 1905 Canadian Ross rifle was a straight-pull military rifle (somewhat like the Swiss K-31) that had the deserved reputation of firing the bolt through the shooter's head if it was assembled wrong, which was easy to do.

Other models of Ross rifles were and are excellent shooters, but the taint of the '05 Ross rubbed off on the lot.

FWIW, I consider the .280 Ross to be one of the most handsome rifle cartridges ever invented.