There's definitely tension in the wrong place or the stock contacting somewhere it shouldn't but I can't narrow down the exact spot or issue. It's a one piece bottom metal model and it doesn't seem to matter which of the two action screws I tighten first, leave loose, etc. As soon as there is any amount of pressure on the action, it starts.
It wasnt properly glass bedded then. Or the trigger is making contact with the stock. If you've ever had a properly glass bedded model 70, you'd know exactly what im talking about. With mine, i pop the action in the stock and it doesnt take much to torque down the action screws, once they start to get tension on them. I dont know what "gunsmith" you had doing the glass bedding, but it is generally customary to check function afterwards. Good luck with it. I hope you get it figured out.
