Since you live in Phoenix, the Glendale Cabelas is in your area. Cabelas has system-wide a number of 16 ga Sterlingworths. Pick the best two and see if they will ship them to Glendale to be checked out. Buy yourself a Skeets bore gauge from Midway or Brownells, and using the tips from this thread give them a once over. It's not all that difficult once you know what to look for. And remember, make the purchase with your head, not your heart. I've done that and regretted it $$$.

Ed