O’Connor found his métier in writing on guns and hunting. In the first chapter of one of his books, The Hunting Rifle, he would provide an introspective view of the keys to his success. “No man’s opinion is any better than his background, his experience and his general common sense,” he commented. O’Connor then hastened to add that he disliked words such as “authority” and “expert” when they were “applied to those who write about guns, shooting and hunting. I am not a ballistician or a gunsmith. I write about rifles as a user and lover of rifles who tries his ****edest to be honest.” His love of guns and their uses in sport, along with a real feel for words and a transparent honesty, helped make O’Connor a great writer. He poured emotion into his columns, feature articles and books. Most of these were written over the course of more than three decades, beginning in 1939 when he became associated with outdoor life. As the magazine’s Shooting Editor he was insightful, opinionated and extremely influential. Almost single-handedly he popularized the flat-shooting, smaller centerfire calibers (most notably his beloved .270).