[RFB 1.52] Torpedo was a dud, sir !

[Kobal2]

I'm at my wits' end here.
Here's the situation : I've got a nice, working, uncorrupted, January 11 1942 save with a perfect attack set up on a pair of Maya/Takao cruisers.

- I know magnetic triggers are going to premature 200 yards out the boat, so my torps are set to impact only.
- I know that, for some reason, my torp depth TDC setting is stuck in meters while the rest of the game is in imperial units - so torps are set to 5 meters, the only setting that'll reliably hit a 18 feet draft ship, what with deep runners and all.
- I know my targets' speed and course to a T by now : 12 knots, 210 degrees, 4500 yards range at the time of saving. I can ping 'em till my fingers bleed, and still they won't notice me. Same about the periscope : I could shine a lighthouse bulb out of it, and they wouldn't notice. They've got no escort, no depth charges, no nothing. Should be a turkey shoot, right ? WRONG.

Out of every salvo of 4 fishes I shoot at the leader, only one explodes, tops (I'm in a Salmon, can't shoot more than 4 in one sitting). I've tried many setups. 45° constant bearing. 20°. 60°. 5°. With PK and using constant bearings. Periscope ranging and sonar ranging. I could hit those cruisers with my eyes closed. Yet every damn time, "torpedo was a dud, sir !".

Now, on to the question : is it supposed to be that way in 01/42 RFB 1.52 ? I know early war Mk. 14s were crummy and failed 95% of the time at a 90° angle, but surely some angles worked, right ? I tried many, many solutions in this pre-set configuration, and nothing gives me more than one lousy detonation out of 4 torps. What gives ? What's the magic angle ? Or is it supposed to be that way ? And if it is, at what date can I expect a modicum of gosh darned certainty that my torps are going to go BOOM instead of *clunk* ?