David,
I also bent a few stocks myself using a similar jig as above.
I also noted a tendency of the wood to pull off the metal on the side where it is supposed to stretch some. I read somewhere that wood bends in fact by compressing the fibers on the side you are bending it towards and there is no significant stretch on the oposite side. I use an oven cooking thermometer that I insert into the rag I wrap around the stock. They say one should reach 200F or higher before bending. It is at that temp that the links between wood fibers come apart allowing permanent modification of the wood. I allow slow heating at a rate of at least 1 hour per each inch of stock thickness. I tighten up the jig to achieve my goals keeping the new dimesnions for a few minutes and then release while the stock is still hot. If it returns past the goals, then I retighten past the initial dimensions until I achieve the goals. I can operate my jig in both cast and drop at the same time.
I apply a clamp with good padding over the stock head to keep that end of the wood together on the metal.
I use the whole gun in the jig as the barrels would give me better alignment on to the jig, but I clamp only the action.
There will be movement of wood around the metal, although minute most of the time.
