I had the same experience with laminated birch shafts....i straightened them, and put 4 good coats of finish on them, and they didn't stay straight long at all.....Seriously heavy shafts though....I found i don't care for the momentum loss, and serious drop after twenty yards an arrow takes exceeding 10 grains per pound. my long bow performs it's best with 585 grain arrows at 23% FOC at 57-58 pounds....i rand some 650 gain arrow though her last week and there was a huge difference in trajectory in my opinion....this was even more so with my new recurve with the lighter weight limb tips...That bow likes 8 grains per pound the best....Matching your arrows to your bow is critical for max performance and arrow flight i'm finding out....Every bow is a bit different too.....
I'll tell you another kind of wood to check out would be Poplar....I'm really liking that wood more and more as good arrow stock.... The down side to poplar is the increased diameter size needed to get your spine.....the fir is a stronger or stiffer shaft in comparable diameters, but harder to work with. i love the fir shafts though......Kirk