07-17-2023, 02:41 PM
A Friend assembled an upper and the bolt/carrier wouldnt go into battery. Traced the issue to the gas tube being to long. When installing the gas tube the guy didnt get the gas tube seated properly. The retaining pin went in the gas block but ahead of the tube instead of through the hole in the tube. Makes me wonder if the gas block is not centered over the gas port which is affecting the gas or gas tube length or both.