JMB's long relationship with Winchester sort of choked off because they were buying the contractual exclusive rights to his designs and then not producing them. It was an early form of restraint of trade.
JMB went to Remington and offered a couple of new designs to them. They bought a 22 LR rifle, but refused a shotgun. JMB and MSB thought highly of their new autoloader shotgun and thought Remington was totally wrong in not purchasing the design. JMB went to Belgium and presented the design to FN. FN jumped on it and made a deal with JMB to be his future exclusive manufacturer. The shotgun design what was to be known as the "Auto Five", then redesigned as the "Sweet Sixteen", etc., etc. Years later Remington acknowledged their mistake by purchasing rights from FN to produce their version of that design which could have been theirs to begin with. IIRC, the story went that Remington had an in-house designer that was working on his version of an autoloader shotgun and the Remington management were convinced by him that the in-house design was just a good as JMB's. It wasn't and never was produced.
The JMB/FN relationship went on to produce the "Browing Hi-Power" handgun and the Browning 22LR Autoloader. And few other very successful designs. Someone can correct me on this; it sticks in my mind that the extremely successful line of Browning designed machine guns produced in the USA for the war efforts were produced by American producers under license by FN. There might be some exceptions to that general statement.
The BAR automatic military rifle was produced by several different manufacturers both in the USA and by FN for our armed services and others. I do not recall where the original design rights were settled. ..............