AR gas/buffer, need help

[Diamondback]

Actually, I think I have a bench-block in my toolkit that was meant for FSB installs... I should note that this is potentially a defense/duty build, my "briefcase AR" project.

 

[DirectDrive]

Actually, I think I have a bench-block in my toolkit that was meant for FSB installs... I should note that this is potentially a defense/duty build, my "briefcase AR" project.

Uninstalls.
Buy the barrel and installed FSB from a reputable barrel shop.

 

[titsonritz]

Actually, I think I have a bench-block in my toolkit that was meant for FSB installs... I should note that this is potentially a defense/duty build, my "briefcase AR" project.

I believe you are referring to a bench block such as this:

BROWNELLS AR-15 FRONT SIGHT BENCH BLOCK | Brownells

That is intended to remove and re-install a FSB that has already been installed by the manufacturer, as I mentioned it requires a special jig the first time around. Plus, to be quite honest, I find those bench blocks pretty much worthless.