|Originally Posted By a308garand:
Use only the bolt, stripped of the extractor and ejector.
If it is truely 5.56 gauge and the GO gauge does not close on the barrel, you may have a .223 chamber.
Check with the bolt stripped first.
I have stripped the bolt for the test. The gauges are marked 5.56 Go and 5.56 No Go. The Barrel is a JoeBobOutfitters 5.56 stamped stainless steel.