Pistol Man's Apprentice

Nine-year-old Daniel Monroe's life is shattered when a wagon train heading west to Oregon from Kentucky is attacked by outlaws and his family is slaughtered. Only luck and reluctant help from a cold and sullen man named Jacob Conrad enables him to survive.
Dan follows Jake Conrad into an uncertain future and although his adopted father remains aloof and forever troubled, Dan learns to love the man who is as wild as the land around them, as uncompromising as the weather and, underneath his gruff exterior, as tender as a mountain sunrise.
Dan grows strong and tall under Jake's tutelage and over time he learns to hunt and to trap, to build and to farm. He learns to read and write as well but most of all he learns how to shoot because no one knows better than Jake that life is cheap on the American frontier, and if a man wants to keep breathing, he needs to defend and protect what's his.

It's a good thing too, because Jake has a powerful and implacable enemy who will leave no stone unturned to hunt Jake and anyone he loves down like a dog. But he has yet to meet The Pistol Man's Apprentice.