Churchill gets to try the prototype bullpup versions of the FN FAL in .270 British and .280 and seals a deal with FN that UK armed forces will buy the FAL .270 in a bullpup configuration if Belgium agrees to order the same weapon and Enfield Small Arms can license build for 50% of the UK order and export to commonwealth countries.
In this ATL, angered at US intransigence, Churchill would rather switch to an FN design and commit them to a non-US round than accept a US round that will be impossible to fire from an EM-2 anyway.
Just a contract and a small arm in two countries (although Canada is also interested). Will it change much?