The myth of Charlton Heston's right turn

Heston was great in "The Ten Commandments," "Ben-Hur," et al. But the news obituaries written about him are interesting: Noting that he marched for civil rights (as seen in this 1961 photo outside a whites-only restaurant in Oklahoma City) and led the Screen Actors Guild, press reports then note his leadership of the National Rifle Association took him in some sort of right-wing direction. But it seems to me that he was just being consistent in his defense of constitutional rights, right?