Yes. You make a metal part, then a vulcanized rubber mold, then pour wax in there. The wax is around 4% smaller than your original part. The additional 1/2% is due to the metal shrinking as it cools.
Going directly from plastic to metal loses only that 1/2% due to metal chilling. We can generally handle that.
Dentists have special rubber that eliminates the 4% shrink. That is why your gold teeth fit darn near perfectly. We did that trick on some UP truck sideframes for which we could find no other provenance. You couldn't tell the difference.
