Wondering why glass bedding screws hasn't been mentioned? I haven't bedded screws on a shotgun but I have done every bg game rifle I own when I bedded the actions. The screws tighten down to exactly the same place every time and I've never had them work loose. I've used it from a .338WinMag down to a .222Rem. and I've not seen any degrading of the glass from wear, recoil or other. I think it would stand up the repeated recoil of a shotgun.

Nothing is foolproof to a sufficiently talented fool.