| Personally I wouldn't shoot lightweight aluminum shafts from a longbow, certainly nothing lighter than 9 grains per inch. Buy a test pack of wood shafts - for an ELB of 50# a range of 35-55 should be fine depending on your draw length. Bareshaft test them and cut them down 1/2 inch at a time until you are in the right ball park. Then buy a couple of dozen in the right spine, weigh them, spine test them and sort them into batches. You will always get at least one or two shafts that are way too stiff (often its the heavier ones but not always). Stick the point end in a drill chuck and spin them through 120 grade sandpaper until they match the spine of the rest of them then finish them with fine grade. You can actually get your shafts very closely matched in spine doing it this way. If I need to take a little bit of weight off I take it from the back end using a taper plane although tapering can reduce spine by a pound or two.
Remember that a spine tester only measures static spine which does not always equate to how a shaft performs when shot. I shoot the most closely matched set and use the drill/sandpaper to fix the arrows that fly right of the group - basically tuning the arrows to my bow and to me. The ones that fly right I can either lighten the point and/or cut them down slightly to stiffen the spine (fine for practice but technically they are not a matched set). Final tuning can be done by small tweaks to brace height and nock point position.
Just my tuppence worth. |