The port hole to the gas block was too small until i took it to a gunsmith and got it bored larger. - Andro Corp Industries AR-15 5.56 NATO Threaded Barrel

Don’t buy it unless you want to pay to get the port hole bored out. It cost me $220 to have a gunsmith test and repair the gun I built. All was good with the gun and all parts except for the barrel. The port hole where the gas block as attached was too small. Had I known the problem before hiring a gunsmith I would have returned it.