I am with Alleyyooper. The only difference in the heavy brass warnings is because the neck on Milspec brass is very thick and could "Choke" the bullet, and the primers are staked. Any good reloading manual should mention this. The original poster did say he switched primers. According to the old NRA Handloaders guide, this caused the biggest variation in accuracy. Way more than + or - a few grains of powder. This was tested by the Frankford Arsenal and published in the Handloaders guide. As far as good and bad brass, it is pretty much a matter of personal choice. I have made chamber reamers and the SAAMI specs on the body diameters of brass is generally .006-.008, but milspec brass is not to SAAMI specs (Maybe it is now, I have been out of it for a while). The military chamber headspace was not even called from the same points SAAMI used, and the European guns had their own specs also.