A gun barrel stamping tool includes a die ram having a first U-shaped gun barrel fastener, a die container having a second U-shaped gun barrel fastener, and at least one die ram to die container fastener. The die ram and the die container each include opposing longer sidewalls and an elongate aperture located medially within each longer sidewall, the fastener being received by the elongate aperture. The die ram and die container combine to form an interior space for receiving a punch die. A circular aperture located medially within the shorter sidewall of the die container receives a punch die fastener for securing the punch die against the end wall of the die ram. The die container may include an adjustment mechanism for widening the interior space of the die container. The U-shaped gun barrel fasteners are located on opposing ends of the die ram and die container.