I hadn't heard of it either, except on one particular site that seems to be frequented more by target archers than anything else--even though it's a "traditional" forum.

The reason I ask is one guy started out talking about the 300 being so common among traditional shooters that practically everyone had shot it, etc. I called his bluff and he started crawfishing immediately. Changed his story 3 or 4 times in a day. It was very entertaining.