I have this box target (chunk rubber mulch), well now it has approximately 4000 rounds of .22 cal. pellets and is getting extremely heavy, you can see the box bulging. What do I do with it? I don't want to just dump all that lead out in the yard, I put enough out there already from my spinner targets. I don't want to build some fancy contraption just to sift out the pellets. What does everyone else do?