I was looking at the file I started to set-up to change some of the settings yesterday, and from the looks of things, you should have depth-keeping trouble from the beginning until mid-1943. There should also be impact pistol issues with roughly 90 degree hits not detonating, and less that 28 degrees deflecting off and not detonating, both until late 1943, but the slight angle "bounce" for the duration (the pistol detonator does not strike the ship). Then there is the magnetic detonator, that should have several various failures, such as detonating as soon as it arms, all the way through never detonating at all, and those percentages fluctuate throughout the war. There will always be magnetic pistol failures. This is also affected by wave height, such that the rougher the weather, the more duds from premature detonations. There really should be more failures though, going by what's in the file now, but we'll do some experimenting and see what's up...
