About: http://webisa.webdatacommons.org/400730010

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Sources indicate that the lowest grade was an A with the highest being an E (fully engraved and ultra rare).
http://www.w3.org/ns/prov#wasQuotedFrom	bluebookofgunvalues.com