later in the war, ive had MUCH MUCH better luck with the "pink" torpedos(mk17s?), i forgot the model number, but they seem to be much more reliable and powerfull. im on my 3rd career and im stuck with the mark 14s right now and i go through the same stuff you do, especially when they explode 100yards before the target !
but i know that skippers back in the day had the same frustrations so i keep on firing and make more trips for refits....