i'm not sure what happened with those short barrel TC Black Diamond rifles. There were a lot of them for sale by discounters and others years after TC quit making them: Could be that they were factory seconds or something.
I've scoped and sighted in 6 or 8 of the short barreled Black Diamond guns and they are tack drivers. There was one besides my own that was problematic: It also had a plastic stock and it came from a discounter.