Depending on your intended use, runout can be as much as .005" or as little as .0005". Once you break the 1 MOA barrier, fine tuning such as weighing each powder charge down to the finest degree, perfect bullet weight, bullet seating depth, mouth thckness, and runout become critical.
For a hunting gun, .005" would be acceptable. For bench rest competition, .0005" would be normal. Long range tactical and varment shooters seem to settle on .001" as max.