I'm looking for a single-word verb that means "to make more accurate".
The OED lists a word that might work, but the context is sort of restricted to an (in my opinion unfairly) small situation set. It lists the word accurize, which is fairly new (its first recorded use by the OED is from 1955), is originally & chiefly a US term, and means, "To adjust or modify (a firearm or (occas.) other device) in order to improve accuracy."
I can't find any other word that means the desired definition.