So,my f75 ltd dst is alot quieter after upgrade but it has lost depth especially in all metal. Anyway,i went to my test garden this evening to check a couple things because yesterday i got a shallow iron signal and my brother came right behind me and dug a minie ball at that spot with at pro. Ok,in my test garden a minie ball at 9" the f75 in disc sens 98,bp,2f hit the minie ball pretty good with audio and numbers were jumpy but i wouldve definitely dug it. Next i go to another minie ball buried at 6" with same settings and it barely hit it with audio but it was a solid iron tone and numbers stayed in iron(solid 2). I re-dug the bullet to make sure a piece of iron hadnt got in there and it hadnt. Can anyone explain this? Ive had this detector for years and i knew it really well before the upgrade. I just cant figure out how it is seeing something deeper and both minie balls are laying flat in the holes. Crazy