590 A1 mariner.....this is used in our military? Just out of the box, fired an s and b 00 buckshot, and the action freezes and will not move. Finally cleared it changed over to fiochi's and after a few rounds, same thing. Took it apart cleaned and oliled. Worked ok with fiochi's....then hung up on a federal 3 inch 00 buckshot. Tore it apart again.....appears to be a burr on the thread line of the breech hanging up the extractor. ??? How could that pass QC? Sent it in.