and when you've done all you can, as above, and you get to feel like youre spending more time fiddling that shooting....you can think on lower profile fletchings, ie: vanes that don't stick out so much - immediate extra clearance!
(It's a short stop cheaper measure that may let your arrows 'come off the bow' cleaner and allow you to keep shooting and improving your form - rather than buying new arrows of the proper spine or maybe going to a higher draw weight that ruins your form - both of which should be considered first as mentioned above..
have you checked your tiller measurements?
Only ask 'cos I set a bow up once with the tiller way-wrong - and totally couldn't get clearance no matter what. Once that was spotted it seemed logical that it would cause problems as one limb 'wants' to stop moving before the other- yanking on the string and therefore nocking point as the arrow disconnects. I'd love to find out that Im not the only dozey plonk that can set a tiller wrong!
