Beware the barrel nut - Strike Industries Grildlok Lite AR-15 M-Lok Handguard Assembly

The barrel nut's threading is too long/deep that the barrel nut would grind against upper receivers before it would engage with the barrel's barrel extension. I have tried two different brands of upper receivers and the result IS THE SAME, the barrel nut would grind against my upper receivers, and in one scenario, it even grind against my ejection port rod. It is not a well designed product, or maybe it is the poor quality control of the barrel nut.