Again, the 5 bona-fide Italian Tipo 2 barrels that I've installed were all of excellent quality with no issues about proper fit, headspace or accuracy.It would be highly unusual for a Beretta or Breda receiver to be off spec. I've owned a few dozen of them, and have used them as the basis for many builds. They were built to a very high quality line.
Having similar experiences with Tipo modified barrels and everyone headspaced fine with one of the bolts I had on hand my bet is still on the fact that the barrels were faulty from the get go. A cascade of wrong 'fixes' has got this whole fiasco to where it is now. Thank the powers that be Marstar is not a used car dealer.