VON CAPO, with all due respect, you need to check your math, and refer to the torps required estimates as listed above by CWorth, which agree with my own experience. Using an average of 2 torps per merchant ship (finishing each off with 15-30 DG HE shells, spaced along the waterline, after the escorts leave the area) you will find that the following are typical 1940-42 good patrol results using standard GW1.1a:
Type VII: 14torps/2torps per ship = 7 merchants (your info lists 8 as record)
Type IX: 23torps/2torps per ship = 11.5 merchants (your info lists 14 as record)
These results fit nicely with the historical records you reference and reflect my own patrol experiences. When executed properly, you should be able to pull down 2 (VII) or 3 (IX) merchant ships on every convoy attack set-up run, finishing them as stated above. With skill and some luck, you can often whack the same convoy 2-3 times over a 24-48 hour period, expending all torpedoes! Using this method, I once killed 13 merchants on a single IX blue water patrol with GW1.1a, although 9-11 is more normal. I believe you could even improve that score by harbour raiding.
If this level of realism does not suit you, then as others have stated, you may be better suited to use the children's arcade version of GW, or just the stock SHIII. Better yet, perhaps you could try shooting fish in a barrel? You might really enjoy that!
