How far away are you shootin? :o

20 yards beyond the maximum range of Mk10(though I bet they are cutting out a bit farther away than 20 yards) I am guessing my guess is that he is firing at them while in range but not realizing that the target is slowly sailing out of range.I used to have this problem way back when.If that is the case then his success rate could go up a bit if he gets new sub and starts using
Mk14s set to slow speed he is already accustomed to getting in to S-boat attack range with all that extra range of mk14s he should be good if the only error is firing from too far for MK10s to make it.