One of my projects for this winter will be building a portable, long range steel target. What thickness steel should I make the plate? How big? Is 3' X 3' O.K.? It is for my current 7RM and I may be making a trade for a .300 WM Mark V. My buddy hunts because it is the manly thing to do. He doesn't shoot until 2 days before the season starts. Last week he gut shot a 5 X 5 bull. He says "hunting is really about the bull****ing and the Budweiser." So I laid a huge guilt trip on him and offered a trade for his Win.Mag.