Matching the ballistics & killing prowess of the .333 Jeffery, is why Elmer came up with the original .333 OKH on the necked up, '06 case, to shoot the same 300gr. bullet at the same speed or slightly higher - seems to me.

The standard bolt actions he used, allowed the smaller case to match the larger one, albeit at much higher pressures - probably reaching 63,000PSI, same as some of the standard 06 BRASS loadings today.