I understand that Yankee Hill Machines will void their warrantee if the user permanently attaches their flash hider due to the mechanics inside. What is AAC's policy as far as permanently attaching the Blackout FH?
No problem. Noveske sells a ton of barrels with our mounts perm attached. Have it done by a competent gunsmith that will confirm that the thread job on the barrel is concentric to the bore with a nice square shoulder and you are GTG.
That said, it needs to be done right, and if you get baffle strikes and it's determined that the mount was screwed up (ie something crazy like permed with a crush washer behind it, etc) then you might be out a few bucks for repair.
The problem with YHM mounts as I understand it is that if you perm it, you have no way of maintaining or replacing the spring that is part of the mount.
as long as the tube itself is not damaged your usually g2g, that is as long as you can pull the internals out afterwards, someone recently posted on how aac repaired his sealed rifle can (i dont know which one) they cut off and replaced his damaged endcap and recoated it