If you dont want to get fancy, or spend lots of money.
Talk a walk down a railraod track, you'll find tigh plates (those steel plates that hold the raid to the cross tighs). They work loose, get screwed up and section crews just leave them lay when they put in new ones. They can take just about any round you shoot at them, rifle pistol or what ever.
If you have a section house (railroad maintance section) in you town go talk to them, they'll give you the old plates to keep from having to haul them off.
You can make falling plate, hanging plates, or what ever your imagination allows but they hold up and they are cheap.
CPT USAR Ret
USAMU Sniper School Oct '78
Distinguished Rifle Badge 1071