Shooting Target Auger Pin These pins work great as a substitute for staples for securely holding paper targets to backers made from polystyrene foam insulation board. We cut these sheets into 2'x4' sections. Each section has plenty of room for two shooters. https://www.lowes.com/pd/Kingspan-Insulation-Common-1-in-x-4-ft-x-8-ft-Actual-1-in-x-4-ft-x-8-Feet-R-5-Unfaced-Polystyrene-Foam-Board-Insulation/999972966
TIP: Revere's Riders recommends that you reinforce the edges of the foam board with 3" wide Gorilla tape. We cut these sheets to 2'x4' and secure each section to a couple of plastic step in fence posts using zip ties. These will handle 10's of thousands of rounds. Happy shooting!
Check out Revere's Riders for top-notch, affordable rifle marksmanship training: http://www.reveresriders.org