12-02-2021, 11:36 PM
The ID of the gas key is set to mesh with the OD of the flared end of the gas tube. If the gap is out of spec or too big, then you can lose the appropriate gas seal. If the button or flair on the gas tube is worn or has a flat spot, it will be out of spec. It is hard to see if the button has a flat spot next to the receiver ceiling. The gauge will find these. Gas tubes should be within spec .180 - .006. If they are undersized it will create an improper gas seal to the gas block or gas key. If the gas key or gas block holes are also out of spec, it will exacerbate the problem even more.The reverse torque test of 30 inch pounds is purposely set under torque spec of 57- 58 inch pounds. If the screw loosens at this lower setting, then there is a problem. If the screw is broken or under torque spec, then the staking will not matter..