PPatch: who are you calling an ancient?
I use a hot plate, a rag soaked with water, and a pair of oven mitts to straighten wooden shafts, including natural shoots for arrows, spears, and ramrods. The wet rag is just a precaution against scorching the dry wood...it's the heat itself that does the limbering up of the wood fibres.
So heat the rod over the element of your stove until it is too hot to touch, but try not to char it. then with the oven mitts on your hands, bend the wood in the opposite direction of the warp, just past straight, and hold it there 'til it cools. when you release it, it will remember that it was bent and end up as close to straight as you want. It's quite easy.