I have a couple of red dirt sites here in TN that are very close to the red dirt of Culpeper, VA. I will be getting a V3 for my own use after what I saw it do in that dirt. I was using a friend of mine's V3 to set it up for him. This is what I found to work best in it:
First off, scratch the preset relic mode. The only thing you need to use it for is a base to adjust the machine so that you can save it as its own program.
Under "search audio" put the machine in All Metal mode. Then go under your Sensitivity settings and up your all metal sensitivity to match around about what your discrimination sensitivity setting is.
Then go under your search frequencies, and select the single 7 frequency.
And this one was just a personal preference but I liked the recovery speed to be at 40. I'll explain why later.
Ummm take the machine out of auto track and put it on manual, and make it a + 2-3 offset. And remember to GB often in that soil.
Keep in mind that basically everything is going to read as iron in that soil....no matter if it's shallow or deep. If you do like some guys and only dig anything that is in the + numbers, you are going to have a very empty pouch. That's where the 40 recovery rate comes in. At that speed, you will be able to tell nails very easy, because they will give a short double blip sound. A minie ball for example, may come in on your ID numbers just like a nail will...but it wont have the double blip sound.
I will be able to know more when I get my own V3 and get to really start tinkering with it. But the results I had by adjusting it like above, made a big difference in the bad soil. You can see the video I did with it on YouTube:
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