blacksmith
.270 WIN
Apparently Mossberg & Tazer developed a Model 500 Tazer shotgun. It appears this project was short-lived and the projectile is no longer available. This likely why these are so cheap.
http://www.ebay.com/itm/2-Mossberg-...304?pt=LH_DefaultDomain_0&hash=item4ad6ea9f30
http://www.ebay.com/itm/2-Mossberg-...304?pt=LH_DefaultDomain_0&hash=item4ad6ea9f30