Disappointing qc - LANTAC Enhanced Full Auto Style .223/5.56 Bolt Carrier Group (BCG)

I have been using a NiB Lantac E-BCG for several years, and wanted the same features without the possibility of a finish that could flake off. The polish and nitride on the carrier is flawless. The bolt however was ground so much after heat treat that many "critical dimensions" had turned purple. The extractor is not nitride as advertised, but is parkerized. That is fine, but it was so short of spec that it couldn't get over any case rim causing the bolt to jam into the extension and a round left in the chamber. Also, the lip of the gas key was jagged. Optics Planet's customer service is great and they exchanged the first for another. Unfortunately, the second E-BCG had the same problems as the first. Very disappointed in Lantac's current QC. They must have changed suppliers for their bolts, because I have a Lantac Nitride bolt that was purchased separately from OP last year, and it's far superior in quality to what they put in the E-BCG.