I tested dozens of those torp shot Contact or Magnetic setting.
There is no difference. They both miss the same under the hull , or both hit the same just at the hull limit.
NO Difference as far as I can tell.
I had the DUD setting OFF. That may make a difference in results people get.
Mogami Heavy Cruiser. 24 feet deep. 27 feet will miss. That is quite a deep Draft compared to print manual.