Re: quick question
Layout die or sharpie on the screw shank, carefully insert, tighten it in, remove and carefully remove.
Look for anywhere that has a contact region that swirls around the fastener shank that would indicate a contact region.
A faint axial mark running along in one spot usually means that you just slid the screw into the hole and touched something on the way in. A "rifling" pathway around the screw(s) is a good indicator that something is touching.