Steel targets at any range need to be just slightly tilted towards the shooter. If you do shoot steel with a high velocity jacketed bullet you will put pock marks on the target surface and they will cause a bullet to come back at the firing line, it's just a matter of time.
That's true. Your steel target, for close range pistol, should have no pock marks for the reason stated.
My Evil Roy Portable Steel targets have the rectangle or circle slanted so the bullet fragments travel straight down into the dirt. Sometimes, when shooting straight away, fragments can hit the support legs and come back a ways. They recommend 7 yds. min. When I shoot that close, I shoot at an angle so the fragments impact away from the legs of the target. You can also get heavier gage steel for use with carbine, and other rds. They handle buckshot fine, and bird shot is good practice when using two targets. NO SLUGS--big chunks can break off and come back.