He states was writing about the 285 OKH in 1939 using those bullets he developed for the 280 Dubiel, the second he worked with CM O'Neil starting in 1937 (the 250 O'Neil). The Dubiel Magnums were before his work with O'Neil (Big Game Rifles and Cartridges published 1936) and Hopkins and it sounds like he had Dubiel enlisted to make a 333 on the '06 case, but Dubiel had passed away.
The whole "OKH" thing sounds like obfuscation; but he does state they were "experimenting" with different parent cases during that time and he had ideas that did not come into finished arms until Dubiel had passed, like the 333.
Its quite possible the slight differences in your dimension findings along with the Elmer's use of the Dubiel cartridges made them create an essentially "identical", but not, cartridge.
I'll try to get "Big Game Hunting" back, and see if there is any help there.
