http://cartridgecollectors.org/headstampcodes.htm (Centerfire)

http://www.afte.org/ExamResources/ga...llery/album01/ (Rimfire)

http://www.cartridgecollectors.org/glossary.htm

http://members.shaw.ca/cstein0/uscenter.htm

http://members.shaw.ca/cartridge-corner/shotgun.htm (Shotgun)

The last is a new one, and our thanks go out to Curtis Stein, who is gracious enough to let us link to his excellent site!