The quality of the steel has a lot to do with shooter safety. Take a look at
Auto-Poppers.
This is from the mgmtargets.com FAQ:
MGM strongly discourages shooting ANY steel closer than 15 yards. Period. Shooters AND spectators (especially children) should always wear ear AND eye protection, regardless of target composition (steel or paper). Any closer than 15 yards presents a significant risk of the shooter or spectators being hit by bullet fragments. Generally speaking, MGM targets will easily handle hits from any traditional defense caliber handgun without significant marking.
Regarding bullet fragments hitting shooters and/or onlookers, ANYTIME you are shooting steel, this is a possibility. I don’t know anybody who has shot steel, that hasn’t been hit by a fragment hard enough for it to draw blood. It is usually so insignificant that it doesn’t even require a BAND-AID®, but I suppose that it could be much worse.
The MAIN reason bullet fragments hit people is because the surface of the target is damaged. Damage is usually the result of 1) the target was shot with a rifle (or shotgun slug, or .44 Mag -or larger-), or 2) the steel was too soft to be a satisfactory target, in which case, traditional pistol rounds could have damaged it, or 3) any combination of the above. If the target face is smooth, bullets hit it and splatter like an egg thrown against a wall. If it is dimpled or cratered, bullets hit it and ricochet out of the craters in any direction. I personally know of bullet fragments from a high powered rifle that flew back over 200 yards, to then hit the wall behind the shooter. (That was NOT an MGM target!!) Damaged steel should not be used, even with extreme caution, regardless of the distance the shooter is from the target.