I just by chance checked my YHM barrel nut and a 5" grinder wrench fits perfect. I even loosened it up and re tightened it 
if you in a pinch and don't want to spend $30 on the tool (i still recommend getting the proper equipment) go for it.
if you in a pinch and don't want to spend $30 on the tool (i still recommend getting the proper equipment) go for it.
