Yes remington did chamber for the 300 weatherby cartridge. Jarrett, Clarence Hammonds and Baer I think all had versions of the 30/ 8mm rm and probably some others. I do like the 300 weatherby but really prefer the Jarrett cartridge with its 35 degree shoulder.The 8mm Remington Magnum necked down to .30 cal is essentially the 300 Weatherby. The only difference would be the double-radius shoulder. I suspect that is why Remington never explored that idea.