I shoot steel alot, 25 to 300 yards.
For 25 thru 100 yards I use my own 3/4" thk 6 x 12 oblong of very high strength steel, which I hang from frame with chain and bolts. This thing has been hit with 7.62x54r steel core, 270win, 243, .308, 7.62x39, 44mag, 357mag, 12ga. slugs, 00buck, etc. It is stout, the steel core stuff is the only thing that can leave a mark, and it's minimal at best.
Ricochet is something I've not been too concerned about in the past. Our range is well constructed and far far away from civilization and it is usually pretty deserted. At 50 thru 300 yards I've not had any issue, but on our 25 yard lane there was a suprise for me a couple weeks back.
So I'm using my bring along oblong gong on the 25 yrd pistol lane the other day, plinking away with some fmj .38 special when all of the sudden I feel a tap on my shoulder like a really big bug just landed on it.
!!! One of my shots smacked that steel, went up in the air, and landed 25 yards straight back on my shoulder! A nice jagged chunk of flattened lead, laying on my shoulder, right next to my face!
Glad it didn't hit me in the face, safety glasses or not.
I've not really changed anything I do because of it, but know that odd things can, and will happen.
Wear your safety equipment.