Target Backstop - Firearms

[Contenderizer]

I live on a farm in a very rual area and have a backyard range (yes, lucky me). Currently I am using a load of sand as my backstop, but this makes it necessary to move my shooting position forward for handguns and back for long guns. I have a nice covered area that I would like to use for firing all of my guns, so a target backstop that I could move seems ideal. I was thinking of building something with a plate-metal back, sloped to deflect the bullets down. I could drag that contraption around with my ATV. I don't believe it necessary to trap the bullets, only deflect them down into a small pit that I will fill with sand. I suspect I won't be using the backstop for my longer shots (the big sand pile works fine for that) so for the most part it will be used close-up for handguns (up to 45 Colt) and out to 50 yards for 22 Hornet. Does anyone know of building plans for such an animal or have suggestions on the gauge, angle, size of the metal plate? Or, do you have a better suggestion?