Green’s Dictionary of Slang

(US) anything or anyone seen as heroic, macho, manly.

1971		Army Reporter Feb. in Maledicta VI:1+2 252: ‘Wow! That was some John Wayne!’ exclaims the wolf, admiring her feat in spite of himself.
1977		L. Heinemann Close Quarters (1987) 175: The John Waynes and Boone County Courthouse loafers and one-eyed Khe Sanh Marines.
1979		(con. c.1970) G. Hasford Short Timers (1985) 107: Craze did a John Wayne. [...] Shot BB’s at a gook machine gun.
1997		E. Little Another Day in Paradise 183: What’s the setup? Creep ’em or are ya talking going in like John Wayne?