lsayre wrote:I've never loaded this cartridge, but I'm pretty sure the most used mil spec powder is Winchester's WC844, which was commercialized (blended?) into more reloader friendly (read that as more uniform in pressure, and therefore safe to use) lots by Hodgdon and sold as H335.
mozz wrote:Not to get into the 556/223 differences but military brass is usually thicker. You should be able to measure the differences on your powder scale. Are you reloading for a auto or bolt? Some powders burn dirty or incomplete in short barrels, i would post what type of rifle and that will get you better recommendations.