If your track is 3/8" from your thumbhole, you ain't anywhere close to a 5" PAP!
Not unless your track is 2-3" from your fingers, which might put the "up" distance at 1.5" or more!!!
Next time do the normal thing:
take a plastic or urethane ball drilled very weak, sand it, play the 4th arrow in the oil and measure the FIRST oil ring, or better yet have REAL, conscientious pro shop measure the first oil ring.