As the title indicates, my newly built Israeli HB on an Imbel won't cycle rounds. I started with the gas adjuster on 7 and one round in the mag, and proceeded to fire, adjust down, etc until I got all the way to .5 on the dial. So now even dialed all the way down I can't get it to throw the bolt back and lock open on the mag. I was shooting 168gr. PMC's. I bought this through the paper in another town far away, so before I drive 3 hours one way to have the guy who built it start messing with it I figured I'd ask the experts here. What can I do?