Go JUST a little further back, to the Savage-built T-24, a WWII rework of the MG42 in .30-06. But the original 7,92x57mm round for which the MG42 was designed was just a tad short for the US .30 M2/ 7,62x61mm round.
Which wouldn't have mattered a decade later as the T44 and M80 7,62 [x51mm] NATO round was under development. All they'd have had to do would have been to blow the dust off the old Savage blueprints and engineering drawings, but they went and reworked what worked, and came up with the M60 instead. Pity. T-24: the U.S. MG42 that might have been.
