The close-up photo of theends of the pins makes it look as though the underside of the forestock is cracked. If that is a crack and not a long scratch, I'd say someone bent the pins to try to suck the barrel down into the stock, but ended up putting so much stress on the wood that it cracked. Could also be that the barrel channel isn't inlet properly or the forestock was very warped.

If it is a crack, I would get some epoxy in there and find a way to clamp it until the glue dries, then figure out if the stock is straight or can be corrected. If not, you can get another stock.