3D, I don't know the answer to your statement, but I suspect Ruger made the change to speed production. In the early '70s Ruger was selling M77s as fast as they could make them. Reducing the steps in making the stocks saved time and a bit of money, thereby increasing the profit margin. A similar situation for the barrels: Douglas couldn't keep up with Ruger's demand for barrels and Wilson barrels were added and then Douglas was dropped. We all know that some of the Wilson barrels were sub-standard (bad QC?). Ruger solved the whole barrel problem by going to in-house made hammer-forged barrels. I agree that the flatbolt stocks were just about perfect.