This has inspired me to do some Zombie Science! (The Cata DDA version of Dwarven Science)
So I’ve created a testing world with basically no spawns, and started as a survivor in a lab, with all stats set to 12, and all shooting skills set to ten.
Spawning in a glock 19, the appropriate ammo, a magazine, and a zombie 2 squares away, I aim at the zombie and find that I have one * (for headshot) Four + (Solid hits) and 6 |s (glancing blows?)
I get the same result from a Remington 870, an AR-15, and a UMP5.
However, at this skill level waiting just one turn to aim increases my steadiness massively, up by what looks like 19 from just one .
This is enough to basically double my original hit chances. Waiting another turn seems to double them again, and by four turns I have no chance to miss. If I steady until the turn that a zombie approaches me (on 50% speed) I pretty much always get a headshot.
So I’d advise gun users to try tapping . at least once before you fire pretty much every time.