I have a BH Challenger that came with a 6" concentric coil, it's great for coin shooting and separating targets, but I'm hoping to get more depth out of my detector. I was wondering if anyone has upgraded to a larger coil and gotten increased depth on air tests? I have heard from some people that it will give me increased depth switching to the 10" magnum coil, and others have said that it will only give me an wider field of detection and no added depth. Thought I'd ask to see if anyone has gotten better results from an upgrade before I bought a larger coil. Thanks for any help you can give. Oh, here are some of my favorite finds with it so far....