I just saw Clay Hayes make a double bow out of all service berry on utube. I have built about a dozen of these double bows over the years. It got me thinking about making a double bow from a walnut survival bow that I built a while back. The bow was 45lbs. that drew hard with poor arrow velocity. I used Osage for the short 2nd bow with near 5 inches of heat treated reflex. The walnut bow has near 3 inches of string follow. I re tillered it to 31lb. at my draw. This morning I chronied the bow . At 37lbs. at 25 inch draw with a 350 gr. arrow I clocked the arrow at 140 fps. average, and the bow draws smoother now. More than likely because of the weight reduction, but a well built self bow has always performed better for me. In this case it was worth it , because I can now handle the bow much easier, and will shoot it more often. If your under in your finished draw weight it is another option to get your bow back up to the poundage your after. Just a thought.