If you have access to a printer that will print on 11 x 17 paper, I have attached a target I put together to help in patterning/sighting your shotgun if you'd like to use it.
Be sure to print "Actual Size" on Ledger (11 x17) paper. Orientation is "Landscape". The outer circle will measure 10" on these settings. It's a tad grainy, but works.