The youngest right-handed player to reach 300 home runs is not established by the search results I could verify, so I can’t give a reliable name from the available information. What I can say is that Bryce Harper is a right-handed hitter who appears in the results as a major MLB power bat, but the retrieved source does not confirm whether he was the youngest to hit 300 homers.

What’s missing

  • I need a verified career milestone source that lists 300-home-run achievers by age and batting hand.
  • The current results only show general player pages and recent news, not a complete historical ranking.

Best next step

A stats database or milestone leaderboard would be needed to answer this precisely.