I think angle torque is the only way to accurately stretch the bolt without using cumbersome gauges. It removes almost all of the variables, doesn't care about wet threads, dry threads or type of lube. The only witchcraft in it is establishing where "zero" is. X number of degrees from zero is always .00X" of stretch.
As an example, Caterpillar 3406 rod bolts are torqued to 70 ft/lbs + 90 degrees. The mains are 200 ft/lbs + 120 degrees.
