We use two primary references for headstamp identification along with a variety of others. These may help, especially the headstamp guide which is difficult to find. I don't know whether either of these was what you were looking for, but here they are: Barnes, Frank C. 1984 Cartridges of the World. 6th Edition. Edited by Ken Warner. DBI Books, Inc., Northbrook, Illinois. White, Henry P. and Burton D. Munhall 1963 Cartridge Headstamp Guide. H.P. White Laboratory, Bel Air, Maryland. Mike Polk