Bolt Lock Up may be causing drag

I seem to have extra drag in the bolt lock up on my gun. I had to drill out my barrel gas port to .178". I then opened my largest port on the gas port selector to .1875". My gun functions with these settings. The head space on the gun is within spec. With the bolt carrier removed, the bolt will close on a .308 Go gauge but not on a NO GO gauge. The only observation regarding head space that may be an issue is with nothing in the chamber, I can not get a .001" feeler gauge in between the bolt and the locking block.