I use both relic modes and use my 10 inch DD coil. When I am hunting in good ground I will run trigger forward and the gain as high as I can without making it unstable. The Desc. is at zero. I have noticed some types of dirt I can get a little more depth with the trigger center, desc. around 2 or 3.
When I am in mineralized ground or trashy spots I will sometimes switch to the 6x10, but I am sacrificing some depth. On the plus side it is more stable, less chatter. Yesterday I was hunting in a pasture and was digging deep 69's. They were around 8 to 12 inches, the signal was weak at times but with good headphones you will hear them.
The main thing here is you have to slow down, once you dig a deep 69, slow down. You will dig more if your patient and slow down and pay attention. What I am hearing is broken high tones mixed with a few low grunts, When I am in a situation like this just slow down watch your vdi, I pretty much will dig anything questionable. Something metal, iron will give you the same high, low tones, but the vdi will bounce, between neg. and a high positive. I will dig these simply because these iron signals could be gun parts, sword scabbards, gun molds, bayonets, etc..
Last week I was in a spot where I had a signal that was very erratic, the low grunts, and occasional high beep mixed in. I was surprised it was a 69 fairly deep, around 8 to 10 inches. I initially bought this detector for digging in the red dirt in Virginia, I attend the DIV hunts, I really got
where I liked it here in Mo. as well. I have never used the stock coil. When I hear that faint beep that is deep, I know I am usually on a bullet, possibly one another detector may have missed. A fair amount of these bullest were deep in a cow pasture, I learned my MXT by digging these types of signals I mentioned and recovering these. This was posted a few weeks ago on a post that is a couple pages back.