Hi Frank.
I hunt primarilyJewelry & Clad first, then do some old Coin hunting, some causual Gold Nugget hunting and practically no Relic hunting.
I have 4 coils: Stock D2, Bigfoot, 6x10 and a 300MM (12"). I already had the Bigfoot coil. I bought the 6x10 on purpose for gold jewelry hunting. I picked up the 300MM because I walked into a steal deal and I liked that coil with the DFX and the M6 and figured I'd be happy with it on the V3 in a straight 2.5 kHz program for Coin hunting.
I've spent all of my time with the Bigfoot coil and have gotten happy with it.
Now I'm ready to start configuring a 6x10 for just gold jewelry.
I've never hunted ground with the D2 yet.
I've never hunted ground with the 300mm yet.
I'd recommend you pick up a V rated 6x10 as your next coil and tune you up a gold jewelry hunter.
I'm thinking about a 5.3 cause I got $100 coupon to use on one, and turn it into a extreme trash something or other.
Good luck,
Mike