Oh ok, I never bought one of those receiver blocks to put in the vice. So all I do is take the upper off the lower and pinch the barrel (at the front sight) between two 6" blocks of 1x4, with the front sight up and Go to town. To change a barrel all I do is clamp the upper receiver in the vice also, Between the blocks of wood of course. Laying on its side, Flat top toward one jaw and the bottom of the upper toward the other jaw.
I should write a book... Gunsmithing on a budget. :D :D

