I picked these silver coins up yesterday from an area that has been heavily worked over the last five years, with a lot of different metal detectors. The reason these coins were missed was because they were all being mask by rubbish, bits of iron,foil pull tabs etc. So how come I was able to find them.
1 Don't trust your VDI numbers
2 Use a small coil. The reason for the small coil is to get between the rubbish items and work around the edges of rubbish
especially around large iron targets.
3 Very little discrimination if any at all. Use tones if your detector has that option.
4 Head phones. Listen for those faint deep targets
5 Remove as much rubbish as you can, and the good targets will start to show themselves.
6 Don't be in to much of a hurry, take you time and swing your coil slowly.
Most of the coins in the photo were mixed in with pull tabs, once I removed the pull tab the coins showed up clearly.
The other photo's are of a 3 pence I found a couple of day's ago under a steel bar.