Hodgen puts out a magazine type manual every year. In that they list a factory duplication load for Winchester cartridges. Using Winchester cases, primers, and powder, with a 55gr bullet. I have found that my .223 Ultra shoots that load real well. Can't remember the exact weight of the powder charge off the top of my head at the moment, I'm not at home to look it up. But my TCR, Mini-14s, and two Handis shoot this load. My hunting partner shoots an AR and his gun shoots my loads well also.