tkunz:
I have little knowledge about bending stocks, but I did check into bending the stock on an RBL 20 ga. I was looking for maybe 3/8" to 1/2" of cast.
I spoke to several smiths including Mike Orlen, who posts here from time to time. All three told me exactly the same thing. A through bolt is tough, but you may be able to get up to a 1/4" of cast. They also said it depended on the type of wood. Apparently some species bend better than others.
Not sure if bending the stock down presents the same challenges as cast.
Mike Orlen's telephone number is 413-256-1630. He lives in Amherst, MA. I have heard nothing but good things about him.
