Well that, and black-powder fouling binding up the straight .45 Colt case in a lever-gun. The bottle-neck or tapered WCF rounds extracted much easier when the chambers became fouled.
And Winchester & Marlin didn't want anything to do with paying Colt to use it's name or cartridge.
There was a whole lot more company brand name & Trademark stubbornness going on back then then their is now.
Marlin called it's version of Winchesters cartridges the "whatever-whatever" Marlin.
Colt called it's version of WInchesters cartridges the "whatever" Colt.
So, the .38 WCF and .44 WCF was called the 38-40 & 44-40, or just barrel marked .38 or .44 by Colt. NO reference made to Winchester, or the correct WCF caliber designation.
And there was also a long-running agreement between Winchester & Colt that Colt wouldn't make rifles and Winchester wouldn't make revolvers.
Had Winchester decided to chamber a .45 in it's lever-guns, they could have easily done it and made the rim bigger and called it the .45 WCF.
But then, the rim would have been too big to fit in Colt & S&W revolvers, and Black-powder fouling would still have caused problems anyway!
As it turned out, the .38 WCF / 38-40 and .44 WCF / 44-40 worked in everyones guns, and everyone went away happy.
Except perhaps the .45 Colt six-gunners that still wished they could get a .45 Colt Winchester to go with their .45 Colt revolver, and couldn't, because of the corporate politics & black-powder of the day!
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