Ron - I’m surprised you haven’t mentioned Winchester’s experimental 46 WCF, which was based on the 50/110 case.
Go here for all I've got on the .46 WCF:
https://www.24hourcampfire.com/ubbt...hould-own-one-at-least-once#Post15973647And then some about how James Watts did the .450 Watts Rimmed (.458/.348 WCF) on an old M1886 .40-65 WCF (rebore) and a new M71 .348 WCF (re-barrel) in 1950.
In 1951 he showed it to Harold Johnson at Cooper Landing.
In 1952 the .450 Alaskan that everyone knows and loves was born.
And Harold "Bill" Fuller who was Harold Johnson's machinist/gunsmith started making the .450 Fuller when ?
It seems that the taper on the .450 Alaskan of Harold Johnson is problem free for feeding, seems to be consistent specs wherever you look if you call it by that name,
for reamer and dies to match.