on a re-nail, i have always found a shiner (sometimes too many). Eric is right about framers pulling out shiners before a framing inspection, but they usually don’t get all of them…gotta look harder. On an original roof from the 70’s or earlier, many roofs were hand nailed with 6d nails without missing. I try to put the puzzle together with age, permitting, and knowledge of the changing nailing codes over the years for my area.
.