It would appear that the steel case "myth" is upheld in the lucky gunner test. The real issue with most steel cased is the Bi-metal bullets and some of the brands have low enough powder charges as to become unreliable.(Tula refuses to cycle my Adams arms mid length piston upper.) Yes if you are comfortable with changing your own barrels and you use inexpensive ones then steel ammo is just fine but when you add in the cost and inconvenience of bringing your rifle to a gun smith that argument kind of goes out the window as well. As always this is my not so humble opinion and your mileage may very.