Home Forums Hunting & Shooting Hunting Rifles How thick of a plate of steel to stop hunting rifle bullets?

I just built a steel gong out of a cutting edge from a loader bucket. It is 24"x12". We plan on hanging it from chains we welded to it, so it could swing. I was concerned about ricochets, but figured as long as it was 500yds+, it would be ok?

Is my thinking flawed?

Thanks.