Ideas for 4'x4' arrow backstop (large)

[TSHOOTER]

I made this out of elastifoam from whitetail industries in Indiana.  I think it took 4 bundles of elastifoam, some all thread and scrap 2 x 8's.  Field points only.  It's held up great for the last 3 years.[attachment=1]

[olddogrib]

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I think mine's the same stuff as Tshooter's, but not as elaborate.  Only used two threaded rods and it's not as deep.  The things 20+ years old and still going strong.  I just re-stack the shot-out slats every couple years.

[Hud]

Horse mats come in two weights, the thick one is heavy. They can be cut to fit on a 4 x 8 sheet of OSB, or plywood and fastened with screws and small washers.  As a backstop  mount it on a wall, fence, or couple of 4 x 4 posts.  If you need a target butt large synthetic bags filled with plastic bags, sheets, makes good target butt.