Thanks for the tips on bamboo. I have no idea what kind I have. They are 24 inch cut offs that I bought on ebay. I didn't use any heat. I shot the 6th attempt elm bow today, 67 inches nock to nock. It has a good back , and I did a lot of belly heat treating. Bow ended up 33 lbs. at 25 inch draw. Through the chrony it shot a 370 gr arrow at 146 fps average. Sort of wonky limbs. I had to cut the arrow pass deeper to get the bare shaft flying right. That is 6 elm sapling bows in six weeks from green to finish. Average of 16 to 20 hours per bow. Using a lot of belly heat treat all turned out with 1 to one, and a half inches of reflex. One failed , and one other one looked like it might fail at a knot on the back, so I wrapped it. All in all not bad, and guys build elm bows for good reason. It is good bow wood. Time to cut some white oak, and hickory, and black locust saplings next, and get back to work. At the same time I started building these bows I had to admit my wife of 53 years to care home with dimentia. The bow making at this time was the best medicine I could have taken for a really hard time in my life. Good building ,and shooting to all.