Best Coil for using an Eldorado (later model) in moderately bad to bad dirt

[BamaBill]

Has anyone tried an 8.5 DD coil on the Tesoro Eldorado (smaller uMax like model) in iffy dirt? Can you get 8" on bullet?

 

[luvsdux]

I've used the 7" DD in moderate soil at an old logging camp area. No bullets, but did hit a rusty can the size of a 3Lb. coffee can at a measured 15" with a strong signal response. Admittedly a large target and due to the rust, a good halo. I would think the 8.5 would hit a larger caliber bullet at 8" or so, but haven't ever tried that.
luvsdux