The USAF F-4s had "iron sights" that were used as the primary aiming resource.
(http://i906.photobucket.com/albums/ac270/puma44/82a3ee8312841ce9c48983eefe0d8208_zps6e014be1.jpg)
There was also the Dive Toss system that had a less than sterling reputation and wasn't depended upon by air crews.
http://combatace.com/topic/36842-let’s-get-serious-about-dive-toss/