pin AND weld? or just pin or weld?

[AZHTfreak]

When I built my 14.5, researched it pretty thoroughly. Pin AND weld is one of 2 or 3 ATF required methods. I dremeled an old drill bit for the pin and had a buddy MIG weld it. He counter sunk the pin hole with a 3/16" so the weld had clean metal to combine with... Of course ATF would have to destroy the muzzle device/barrel to confirm it's done right :-|