Hit them they light up....
3 Volt red LED and 2 x 1.5 v button cells.
Step 1: Battery Bit
Drill a 1/4 inch hole 1/4 deep and a small10th inch downward hole into the 1/4 inch hole.
Use a 1 1/2" x 3/4" baton, about 1 foot long.
Push one leg of the LED down the small hole.
Push the batteries into the 1/4 hole, and suspend the other leg over the front of the batteries.
Step 2: Target Disks
Use a hole saw and cut out 2 inch disks.
Staple a ribbon of cut up soda can, to the back of the disk.
Attach the disk to the front of the batteries.
Step 3: Armour Plate
Cut out circles of soda can, these are glued to the front of the disks.
It protects them against damage for a while.
Step 4: Face Off
I used the usual marker pens to add images to the targets.
(The targets below are the destroyed old knock downs, that don't have any armour).