Headstamp N 7 308

[pierrody]

What does the following headstamp mean:

N 7 308

 

[sunray]

'N' is/was used by several countries. The '308' indicates hunting ammo vs milsurp though. So it might be the National Cartridge CO of Belleville, IL.
What bullet?

 

[pierrody]

All I have is the brass.

 

[sunray]

Hi. There's a list of headstamps here. Not complete though.
http://cartridgecollectors.org/headstampcodes.htm