From Tactical Life:

Eugene Stoner was, by all objective, accounts a visionary. As a speculative venture while working for the Fairchild Engine and Aircraft Corporation in California in the mid-1950s, he designed the earliest iteration of what would eventually become the M16.

Applying aluminum casting technology and advanced polymer science perfected for the aircraft industry in World War II, Stoner designed an elegant, lightweight rifle that rethought what it meant to be a military weapon. Where everybody else in the world used Parkerized steel and walnut, Stoner used aluminum and plastic.