
Disclaimer: no settlers were harmed in the making of this answer. I VATS-targeted a stationary settler from two predetermined distances and checked the to-hit percentage for the target's core/body.
Double-Barreled Shotgun: plain, sighted (no mods improve hip fire no scope). Institute Pistol: plain, sighted, scoped (no mods improve hip fire).
Assault Rifle: plain, sighted, scoped (no mods improve hip fire). Hunting Rifle: plain, hip, sighted, scoped. Combat Rifle: plain, hip, sighted, scoped. 10mm Pistol: plain, hip, sighted, scoped.
Note: If a weapon used Scoped mods, I attached a scope if it used Sighted mods, I attached a reflex sight. Then I remodded them as follows for hip fire, sighted fire, and/or scoped fire, adding only mods that directly mention affecting hip/sighted/scoped fire. I de-modded weapons of 6 types down to their base configurations.
In some cases the sighted version of a weapon (with a sighted mod) will perform significantly better than the scoped version (with a scoped mod). Prefer mods that improve sighted fire rather than hip fire. So two very general rules if you use VATS often: sighted fire may be treated very differently from scoped fire. whether or not the VATS animation shows you looking down the sights. whether you're looking down the sight just before hitting the VATS key. The following have no effect on whether VATS treats something as hip fire or sighted fire: neither sighted nor hip fire for certain weapon types. Summaryīased on testing so far, VATS considers weapon fire to be: If you test other weapons or find this is simpler than it seems, please let me know. I ran over 50 tests (20 modded weapons of 6 different types from 2-3 firing distances) before running out of time and patience.