In reading your first post it sounds like you tested your head space before you tightenen up your barrel nut. If that is the case you need to revisit that very important step in the operation after you have tightened up everything. When you tighten up the barrel nut this will pull the barrel forward, creating your headspacing. That is when you use the Go-Gage with the single thickness of Scotch Tape (trimmed to avoid overhang).

Jim Briggs
NSS