here is a link http://www.ecra.info/start.php?main_cat=9&sub_cat=108&access=view&exp_sub_cat=108
I think from what I can gather it stands for the small arms ammunition factory who made the cartridge. It was apparently an Australian firm. If you look at the cartridge head on some 223 brass it will carry a stamp of LC. The manufacturer was Lake City and so on. You find REM, WIN, and others. NORMA comes to mind. Different brass wears differently than others. It can vary from one batch to the next by the same manufacturer. If you reload and shoot a lot and lean toward the hotter loads. It pays to inspect it closely between each loading. Be safe hope this helped some.