I meant more in the sim.cfg "Max error angle", which would also affect the enemy AI. This is what FotRSU has, with "Stock" values after the ";" comments:
[AI Cannons]
Max error angle=5 ;[deg]3
Max fire range=10000 ;[m]6000
Max fire wait=5 ;[s]12
[AI AA guns]
Max error angle=2 ;[deg]5
Max fire range=1600 ;[m]1500
Max fire wait=7 ;[s]7
You could also maybe noodle in the CrewMember and other upc files in the Save folder, and increase the crew's skill (I'd probably mess the game up), or just have them do gunnery practice. Every time you go to surface, battle surface and shoot a few rounds... Put the best people on the guns, and show 'em how to do it every once in a while - just don't lose track of the situation... Was it lurker or Traveller that had a practice target?...