Personally, I don't think it really matters. If you have a good barrel inlet, along with the tang, you could go ahead and do
the lock. If I were to do it this way, I think I would put a clamp on the barrel to hold it down in proper position when I
locate my lock. Then, after you have the lock inlet, you can do the trigger and plate, that way you can install the tang
bolt and, probably at that time I would also install the underlugs and pin the barrel in place. As I said before, it all has to
be done, but I don't think it really matters as to the progression..........Don