08-11-2019, 04:53 AM
What he said.
I've built a half dozen Grendels, 20", 16", and 12.7". The gas system ran fine on all of them, except when my gas block wasn't aligned correctly. Work with your gas system until the bolt locks back after firing a single round. I don't know the details about your specific barrel, but it is possible that the gas port could be undersized. It seems like I remember hearing once that BA undersized their ports, assuming that they would be used with a suppressor.
I've built a half dozen Grendels, 20", 16", and 12.7". The gas system ran fine on all of them, except when my gas block wasn't aligned correctly. Work with your gas system until the bolt locks back after firing a single round. I don't know the details about your specific barrel, but it is possible that the gas port could be undersized. It seems like I remember hearing once that BA undersized their ports, assuming that they would be used with a suppressor.