Hunting an old home site, I was leaving the 76 targets and decided to dig one. It was a nice token. I dug the 76 signals the rest of the day...all zincolns. At another site that I had hunted several times leaving most of the zincs, targets were getting scarce so I started digging those pesky 76 and I dug a 1911 Canadian large cent. If you leave those zinc signals, you are going to leave some good stuff in the ground. You just have to decide if its worth digging all those crusty zincs to get a keeper every now and then.