Hi, I'm new to the gun community and am looking to build my very first AR. I am a little confused when it comes to barrel lengths and which barrels lengths constitute an AR pistol or SBR. What is the minimum barrel length without the muzzle device in Michigan to make a Rifle? I am leaning towards a 16inch barrel for my build but before I purchase my barrel I want to make sure that the gun will be a long gun and not a pistol or SBR.