i have this coil for my ace 250 it gets good depth but after 45 minutes i find myself just about dragging it around. Gets front heavy fast i turned to coil around and it seemed to make a big difference with being front heavy and also the back of the coil is more sensitive so it works even better when pinpointing. Turn it around and try it I think you will feel the difference. My issue is i need to shim mine or something because it doesn't tighten to the shaft very well and wants to keep falling on its nose.