My shooting buddy came up with this years ago,we use them to shoot 300 yds and beyond.On a good day you can see big bullets with the naked eye at 300 yds.At 100 and 200 we just use printing paper or card board with 1/2 in or 1 in circles.I like the small see em dots myself.If you're not useing a black target you can usually see the bullet holes with a scope or spotting scope.
Below is what ours look like