We used to shoot out at my grandparents place where the actuall battle of fallen timbers took place, major turning point of the warof 1812. Our back stop was portable, cuz gramps didn't want to alter his way of mowing, ever.
Railroad ties we stole from the tracks down the road. Stacked at least 5 high and a minimum of 2 deep on the top. It was about 5 deep on the bottom. Even more if my uncle was out there with his m16. So it was built like a pyramid on the back side. Then we had wings that went out on either side that were at least 6 foot long. Again railroad ties. These were 2 deep also and the same height as the main back stop. Then a muti layered roof of plywood and 2x dimensional lumber was layered on the top, covering the entire "u" shaped opening, weighed down with cinder blocks. Another railroad tie was used as the target stand.
I was always the one to build it and nobody would help, bastards. It would take me about an hour to assemble it properly. Longer to dismantle, due to the clean up.
Towards the end, my uncle brought over a steel plate, about 1.5 inches thick. We used this , with the top angled towards the shooting line, as an additional backstop. When this was used, then he would go full auto with the military ammo he borrowed.
We never ever ever had richocet. Gramps would not allow it as his apple orchard was behind the shooting area. If you damaged a tree, you was dead meat. period. His trees were his best friend because they didn't talk back like grandma.
But, there is no target better then an apple, you know when you hit it.
There would be about 8 of us out there shooting.
Guns used,
50 cal musket
m16 full auto with military ammo
22 long rifle
22 shorts
.177 cal bb's and pellets
22 cal bb
30 cal
30-06
45
44
38
22 target pistol
30# long bow
15# recurve bow
45# compound bow
2 crossbows using leaf springs borrowed from the Jeep plant as the bow, pull undetermined, but it took two adults to cock the things.