Well, let me think of options:
1. I assume you are looking for gold nuggets? Dig all the non-ferrous to get the gold, including all the bullets and shell casings.
2. Discriminate out even more readings until you dig almost no bullets and shell casings, almost completely eliminating your chances of finding gold. But you will not dig bullets or shells casings.
3. Go somewhere where there are not so many bullets and shell casings.
You pretty much have to dig bullets. Lead and gold read the same and bullets get all tore up and so vary a lot. I do not mind noting the VLF of a particular troublesome shell casing if the are hundreds or more and ignoring that particular reading as that still leaves lots of potential nugget signals. But at the end the person that then digs them will find the nugget you missed.
Steve Herschbach