i am new at this sport and this may be a stupid sugestion but if the 11 ring is getting shot up and the scores are a problem, why don't you put the 11 ring in the 8 ring 4 inches or so from the 10 ring, if your good enough to hit it you will shoot for it. less people will take the chance saving the centers, less damage to targets and scores will be in a more even playing feild. then you will have to do nothing else to the class, and the shooters that have the ability to hit the eleven without giving up a bunch of 8's deserve to win, it would also be more challenging to them, i think everyone would be happy. the scores and the targets will be taken care of.