How thick should a steel target be for high power rifle?

[Art Eatman]

I set up any steel target so that deflection is downward. Five, maybe ten degrees of slope, anyway. Sort of a "general principles" safety thing.

 

[bailey bud]

hopefully, the target isn't in the playground when you shoot it!

I learned real quick that a metal spinning target won't spin for my .30-06 150 grain bullets.

 

[tobnpr]

I set up any steel target so that deflection is downward. Five, maybe ten degrees of slope, anyway. Sort of a "general principles" safety thing.

Yes.
Here's mine- by hanging the plates from the back side, you automatically get them to hang at a slight downward angle. This directs the fragmentation and energy right where you want it- in the dirt