Yes, for close range stuff you need to be shooting static targets cocked down at a 20 degree angle or more. If that swinging one lines up just right on a hit it can send some stuff back at you pretty fast.
^^ This. For rifle, I won't shoot steel closer than 200 yards. I have seen fragments come back, and it's not cool at all. For handgun, I'll shoot angled steel from 10-15 yards with eyes and ears on.
The issue with rifle rounds, mainly 223/5.56, is that close range (inside of about 150 yards) the rounds tear up steel with divots and pitting, even with AR500. There is so much speed and energy into a .224" area, that it can almost cut right through steel due to the velocity. If you do want to shoot steel at close range, go to the frangible bullets. like stated. The core of the bullet is a compressed metal powder, and will become a dust cloud when it hits. Do not use regular bullets for close in. Bullet fragments coming back at you are not cool!!