The 1/2" thick 12" steel target is recommended for use at 300 yards (4 minutes of angle). 

We use a water bath precision plasma cutter to cut all of our metal targets. The rifle target mounting holes are designed for 1/2" carriage bolts.

One mounting option for this target plate is an adapter that bolts to the target and fits over an angle iron stem.

We also have an A-frame with pendulum, that disassembles, without tools,  for transportability.

Other target product information can be found on the ' Rifle Target - Homepage'