G7a
6,560 yards (6,000 m) / 44 knots
8,750 yards (8,000 m) / 40 knots
15,300 yards (14,000 m) / 30 knots
This was the theoretical maximum range of the Wet-Heater propulsion system. External factors (temp, water current. water density, wave action) would all have significant effect on the range.
However, the G7a was not equipped with a self-destruct mechanism. No German Submarine G series were so equipped. So if your G7s are detonating, it is not a factor of the range of the G7a, but with the exploder mechanism (pistol).
The Germans had their exploder problems just like the Americans did. Both the early impact and magnetic pistols were prone to premature detonations.
Like the other respondents, I also recommend setting your torpedoes to impact only.
I actually found that the shallower depth “seems” to do more damage than deeper hull hits.
Duds and prematures stynk. To me, if a ship is worth one torpedo it is worth two just to make sure. Few things stynk more than getting the perfect setup and launching only one torpedo and losing the dud/premature lottery.
Personally, I don’t ever shoot over 1,500 meters with the vast majority of shoots between 700 and 1,000 meters. Closer is better.
If you don’t have burning ship fragments landing on your submarine, you are shooting too far away
Good hunting