only thing i really did to the siyahs was to round the square edges off the front.im really happy with the whole thing so far, even though i havent gotten to shoot it. the siyahs made me nervous, even though i braced it and drew it before doing anything. as far as the sinew,ive used it quite a bit for diferent things here and there. my string made of it is 14 strand, i went by the norm for b50 just to be safe. it hasnt really stretched yet on my longbow, its been the same every time ive braced it. cant remember if it was that string or something else, but i remember pre stretching somethin.lol