Right now we have an in progress TL about the adoption of the Pederson 7mm cartridge for the US army pre-WW2, but could the US for some reason, say being on the receiving end of a slightly earlier StG44 in Normandy, decide to adopt the Pederson 7mm cartridge post-WW2? That was right as the British were working on their own .270/.280 rounds (about 7mm) which had nearly identical performance to the Pederson model (as the result of facing the StG44 in combat in the Netherlands apparently). Could that be a potential option for the M14 and if so, would it make the Battle Rifle viable? Whatever the US decided on probably would become NATO standard and it would work for the Brits and FN, as their rifles of the late 1940s-early 1950s (EM-2 and FAL) would accept it with some modification considering that the Pederson and British .280 rounds were both developed and chambered in those guns before the US forced the historical 7.62 NATO on everyone. Might it then prevent the rise of the M16/5.56 combo, which apparently got off the ground because of problems with M14 procurement?