My sister in law has an old savage 67H pump 12 ga that seems to have an issue with the action lock it does not consistently lock closed when pumped it seems to work most of the time when the gun is pointed up but unlocks when brought back down it also works seemingly every time if the gun is held level but upside down. It seems like there should be spring tension on the lock mechanism but there isn't? I would love to get this old gun working again if anyone has any thoughts or experience to share