Identify this bolt?

[Castle50]

Looking for a 183DC Bolt 410 Mossberg.

http://www.ebay.com/itm/Mossberg-410-Bore-Gauge-Shotgun-Bolt-YY11/301162010005?_trksid=p2045573.m2042&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D22425%26meid%3D6416771303237213667%26pid%3D100033%26prg%3D9723%26rk%3D2%26rkt%3D4%26sd%3D400696544658%26

Looks similar, but not sure on extractor or what changes were made to the bolt themselves over the lifespan of the model.