No through bolt. I use two heat lamps and tin fixtures with clamps bought from Home Depot and a old sock dipped in cooking oil wrapped around the wrist. A old shoe lace holds it in place. After making sure all screws are tight the gun is laid on a bench with the stock over the side. Put a couple of bags of shot, or something heavy, and do the same on the end of the stock. Measure down to the floor, and every half hour check it. When it bends to what you want, or a bit more to guard against spring back, turn off the lights. Wait a bit, say a hour and remove the weight on the stock and see if it stays. You can't hurt anything this way. It doesn't cost much. Now if you were bending down you'd have to make sure the grain of the wood didn't run out along the top of the wrist. Same with cast. But even with them you're not forcing anything to happen. It will only bend if it wants to. I've cracked a couple using a fixture with a threaded rod and nut. I'd just turn a nut and it would move the stock the way I wanted with a nylon strap around the stock. I went to this way and never cracked another one.
