[Frank P]

I would think filing a very small amount of metal from under the "nose" of the lug would allow the FE iron to engage the notch more smoothly.

Edit: I filed some metal from the interior notch, not much, but enough that the FE now goes on with a rap with the base of my palm. I think that’s good enough for now as I am not comfortable removing metal or any other non-reversible gun tampering. Also, I can’t complain that those lugs aren’t sufficiently hardened!