1/4in foam meat tray.. I have a hotwire cutter and other tools but with patience you can copy my results.
the one pictured i used my hotwire to cut the disks and used a soldering iron to burn the holes.. just clam the disk into the turret and take it back apart there will be clear marks of where your holes need to be..... now I use a .45acp shell as a hole saw.... .50ae would be better... on the maverick it allowes me enough room to use tagger darts
this works extremly well with the dart tag blaster and my rapidfire20 although the rf20 took me 3 tries and half the night to get all the holes to line up
don









