RE: New nocks DO make a difference...
I agree on the new nocks, or at the very least keeping some around. I found a few X-nocks that came with some Beman Black Max arrows were loose after a few shots and actually stayed on the string after the shot. Worried that it was the shafts, I bought some new X-nocks and found some of the nocks that came with the shafts were just not fitting as well as the new ones.