No need to play he said she said. Show me pictures of McGowan's threads. Show me pictures of their machine work.
And they made three of those barrels like that for me. I still have two of them under my bench. And those were replacement for a used barrel I bought of theirs that had out of spec threads on both ends. So that's 4.
And I have an ar15 barrel from them with similar looking muzzle threads and the indexing pin on the barrel extention stuck up about 1/4" past the lip. It shoots good though. Kinda scary to wonder if the thread interface with barrel extention is safe. So that's 5. I saw one in the PX with threads like mine and asked when it was built and it was 2019 or 2020. So that's 6, built over a 5 year time frame.