OK, please I need help, I need to make 14 or 15 inch long target arrows for a 30lb bow. I need to use 2-fletch. I had thought to use bamboo shafts, there is no spine to worry about - yes, this is for a crossbow. I have absolutely no idea whether bamboo is a good choice for shaft material or how to determine what a good diameter for the shaft would be. Is there any way to work out the optimum total weight - this is for target work, broadheads are strictly forbidden over here. Also, I need to have some form of two-fletch but I haven't mastered a conventional three-fletch yet, any pointers on a nice simple 2-fletch method?