THey beefed up the grip section to try to make it stronger. I have had several T/C buttstocks split on me, all with the 209x50. When you load the 209x50 you can general quite a bit of lateral pressure on the buttstock and it can and does split right behind the hammer. YOu might not notice it until you fire your first shot after splitting it and feel the action loose in the buttstock. I glass bedded my boyds laminated stock to help strengthen the frame to buttstock union.
It is much beefier than the regular encore buttstock, and especially the synthetic stock, but it needs to be there for strength.