Mystery Item?

[emmagee1917]

Something similar was used over here . Ours had a student lay down behind a rifle fixed into position on the floor and look through the sights . A second student moved the disk across a blank paper by directions of the shooter . When it was in the proper place , the instructor either used a pencil or straight pin to mark or punch a hole through the hole into the paper . The disk was just a black disk .
Chris