1. IF you have a clear shot at an Escort/DD try so, if hit and sinks ok, if it doesnt get your sub deeper and leave it alone, DD's are not worth the trouble
2. NEVER surface when other DD's are comming or around. this is going get urself killed.
3. Deck gun, its not as the stock anymore, the damage model doesnt allow you to just shoot blind at it so it would blow up in hollywood style, shoot at the Water line to get it down.
4. Ramming in GW is a suicidal move , this damage the Hull so bad that you are screwed when you need to crash dive.
also knowing the damage model doesnt always result in a direct sinking, sometimes you have to wait, I have hitted a DD like that, it continued like nothing happen but I saw his hull dissapearing under water and at the sudden her butt sinks and there she goes. you have to be patient sometimes.
Greetz HunterICX
if you want to have more firepower
remove TGW mod and continue with stock sh3.
because I cant think of any tweak that bumps up the firepower