This might not be occurring in more up-to-date copies of P&N, but v2.5, for SE4 v1.49, is displaying some odd behavior with
Planetoid Core Mount weaponry -- combined with the Religious Talisman.
Specifically, the Mount adjustment to accuracy appears to be applied AFTER the Religious Talisman "sets" accuracy to 100%.
P&N's Planetoid Core Mount (CM for short) imposes a -30% accuracy penalty. Well, on a Talisman-equipped vessel, CM weapons were displaying (and behaving with) 70% accuracy, not 100% (I guess prayers only go so far, eh?).
It's not a PROBLEM, just an observation. Modders might want to take this behavior (if it holds true in SE4/Gold Versions) into account when deciding the effects / existance / etc, of the Talisman.
Personally, I'm considering making it a MOUNT (or rather, a series of mounts), giving (maybe BIG) +accuracy, rather than a component.
With the same ranges of sizes, but, more expensive than the non-Talisman Versions ... so you pay "per gun" rather than one, possibly bargain-rate lump sum.
Thatis, *IF* such abilities can be put onto a mount ... I certainly hope so!