Quote Originally Posted by sharpshooter View Post
No go gauges are meant for production situations. It's an easy way to tell whether something is within production tolerances. Most professional gunsmiths don't bother with no go gauges on custom built rifles either, there are better ways to measure than feel. The most sensible way is to use a go gauge and a strip of plasti-gage. It will tell you exactly how much clearance you have past the go gauge.
There is the key, Professional gunsmith does carefully set the headspace using plasti-gage. The average guy trying to learn how to install more than likely can not read plasti-gage. Go,No gage gives the average guy a method of doing the job.