With the exception of the 410 bore, the gauge of a shotgun barrel indicates the number of round lead balls, each having the bore diameter of the barrel, that together weigh \(1 \mathrm{lb}\). For example, a shotgun is called a 12-gauge shotgun if a \(\frac{1}{12}-1 \mathrm{~b}\) lead ball fits the bore of the barrel. Find the diameter of a 12-gauge shotgun in inches and millimeters. Lead has a specific weight of \(0.411 \mathrm{lb} / \mathrm{in}^{3}\).