A Price on a Gunsmith's Head

It is not unusual for an attempt to be made on the Gunsmith's life, so when someone tries to ambush him he's not all that surprised. But when it happens again, and he discovers that someone has put a price on his head, he must discover who and why? A woman from his past? Or a relative of a man he killed? He follows a trail left by the "unofficial" wanted poster he finds, and must dodge a barrage of bullets on his way to discovering who put the price on the Gunsmith's head.