I use a few tools to do my pinning.
I made a threaded stud that clamps the recoil lug to the face of the receiver with OD that matches the lug.
I use a recoil lug holding tool to then clock the lug (the type that screws to the front actions crew and holds the lug in place while tightening).
Then screw action in action V block, line up the hole, and drill away. Maybe not the best way but it doesn't require any measuring for the setup. All the tools just automatically line things up. I made all the tools to make sure things line up correctly.
