01-25-2020, 03:09 AM
Having been in the machining/manufacturing arena for over 60 years, I would be astonished if the process were not:
1. chamber the machined barrel
2. Machine the barrel extension
3. Broach the extension
4. Install the index pin in the extension such that it is clocked (or timed) with the broached feature.
5. Torque the extension to the barrel.
6. Verify the headspace.
7. Drill the gas port in alignment with the index pin.
To attempt to rely on a pair of machined threads to reliably establish a radial alignment is something I would expect from a rookie engineer.
Most likely, AA does not want to invest $100 in a new barrel assembly to make it right. The odds of finding another machined extension assembly that will align correctly and maintain headspace are 2 -- slim and none.
1. chamber the machined barrel
2. Machine the barrel extension
3. Broach the extension
4. Install the index pin in the extension such that it is clocked (or timed) with the broached feature.
5. Torque the extension to the barrel.
6. Verify the headspace.
7. Drill the gas port in alignment with the index pin.
To attempt to rely on a pair of machined threads to reliably establish a radial alignment is something I would expect from a rookie engineer.
Most likely, AA does not want to invest $100 in a new barrel assembly to make it right. The odds of finding another machined extension assembly that will align correctly and maintain headspace are 2 -- slim and none.