Never heard of a "special" barrel, but am sure no expert on 1911, but can tell you this with good certainty: 1911s made in that era often develop permanent bending of the slide, before cracking begins to take place, due to impact with the frame. This bending is not visible, early on, to the naked eye, but it causes binding between the barrel and slide, after the barrel drops down out of "lock-up".
One of the "fixes" I have seen involved removal of metal from the locking lugs of the barrel, to allow free movement of the slide. Such a gun, upon continued use, will eventually exhibit cracks on either side of the slide, originating along it's bottom edge, and progressing straight upward, at a location immediately rear of the lower front portion of the slide which encloses the recoil spring. |