Nick is an excellent choice, you won't go wrong there. Definitely make sure your vise is sturdy and well mounted as the last 1/16 inch takes about 150-200 pounds of torque to set the barrel. Takes just as much to loosen also! Since the block is not round but fits the flat contour of the barrel, clamping it isn't a problem, but making sure the vise won't move can be. Watch out for National Ordnance receivers also, I crushed one once as they are hollowed out under the spring tube housing.