I use facebook sdk 5.1 in my Unity3D project for iOS. When I post player new high score to facebook :
private const string scope = "email, publish_actions, user_games_activity, friends_games_activity";
public void PostResultsToFB(int bestScore) {
var scoreData = new Dictionary<string, string>() {{"score", bestScore.ToString()}};
FB.API ("/me/scores", Facebook.HttpMethod.POST, PostScoreCallback, scoreData);
}
Scores are posted to open graph. I can take it back from player and friends into my game leaderboards.
But I not see game stories on news feed and timeline.
I know story posted only when a player earns a new high score or beats a friend's score.