AA barrels are very good but 9/16x24 thread pitch might not be compatible with all suppressors. PSA uses 5/8x24 thread pitch on it’s 6.5 Grendel barrels. If using a suppressor with an 18” barrel you might consider an intermediate lenght or rifle length gas system. If using a suppressor I suggest an adjustable gas block or adjustable gas carrier.
https://palmettostatearmory.com/psa-18-r...g-ch1.html
https://palmettostatearmory.com/psa-18-r...g-ch1.html

