Safe distance from AR500 targets

[Pappabear]

I bought several quality steel targets. They are 3/8 thick. How far do I need to be from targets to shoot with my pistols: (9mm, 40, 45ACP) and my 5.56 AR's?

I am concerned with safety and ruining the targets.

[kmrtnsn]

You are talking frangible ammo, right?

[Failure2Stop]

Using 9mm FMJ- 7 yards, 5.56 M855- not less than 100 meters. If you want to get any kind of life from the targets it is recommended to used non-steel cored ammo at not less than 100 meters. Even non-steel cored ammo can and will penetrate armor steel and dig divots the strike face of steel targets. The extended range will reduce the probability of sucking splash and spall.

Ensure target is parallel and faces downward at about a 15 to 20 degree angle, which will throw the splash and spall into the ground instead of in all directions around the target. The ground below the target should be soft and preferably sandy to reduce bouncing fragments. If you are using 5.56 at 100 meters it doesn't really matter all that much, but it certainly won't hurt.

Using frangible may allow you to get closer safely, but it is mostly to extend life of the targets and walls in shoot-houses.
You should dedicate the target you intend on shooting with rifle. As I said before- pointy, high velocity bullets will crater the strike face. This isn't too much of an issue if it is out at 100 meters or more, but if you bring it into pistol range there will be serious dents to affect the splash pattern, possibly and probably negatively.

These recommendations are based off of military SOUMs, and are at the high end of safety limits.

[JSantoro]

Beyond what's objectively allowable for the grade of steel, there's also the concern of whatever restrictions may be present on the turf you're shooting them on. If it's your own ground, no sweat. Otherwise, you need to ask your host.

For example, we did a shoot with some folks aboard Ft Stewart. We're thinking that we're cool shooting 500 brinell steel @ 100m using M855. Along comes the Range Control Guy, who says "Tut tut, no closer than 300m, period!" Which tells me that somebody did something stupid and got somebody hurt at some point, causing an ORM meltdown and subsequent over-reaction. We have to shift our whole course of fire.

Fast forward to a Marine range, Range Control Guy says "Frangible pistol 3m, ball 7m. 5.56 or 7.62 rifle, 100m."

Point being, find out the rules of your real estate, too. They may be more restrictive that what the material is capable of safely performing.