I wouldn't consider either 8mm or 35 common, and I would highly doubt any new cartridges coming out in those.
Rob
Depends on what part of the world you're in...
Winchester launched the 325 WSM 15 years ago, and the 350 legend even more recently. Personally, I'd welcome a Weatherby offering in either caliber.
Different strokes for different folks.
I won't say the the 325 WSM is not a decent caliber, but let's be real, how many are they selling?? And far as I know winchester still the only one offering ammo, which mean not enough demand for any one else to produce ammo. Same with the 350 legend, a straight wall cartridge for limited purpose.
If there was any real demand for any 8mm or 35 caliber, bullet companys would be developing modern bullets for those caliber's, you don't see that happening.
I agree different strokes for different folks, but just because a few folks would like to see a weatherby in every caliber, I highly doubt there is even close to enough demand of it to make them any money, to even cover the cost of R&D.
Rob