Just discovered (RE-discovered?) a significant accuracy issue:
Suffering from my CB's recoil, I installed a VERY thick and pampering shoulder pad. (actualy, it was a stuffed Snoopy puppet

). problem solved. However, accuracy was crapy (didnt make the connection at the time).
Now I changed to a thin foam pad, and PRESTO! groups shrinked by 50% !
Apparently, the soft pad allowed the CB to move on recoil, and that movement changed dramaticly from shot to shot. probably due to how hard I grasped the bow, and how hard it was pressed againt the shoulder.
The surprise is not the effect itself, but how significant it is. Take it into consideration when wearing heavy clothing.