I bought a set of Lyman 30-06 dies last spring because I couldn't get RCBS or Hornady dies. I fought with the sizing die for several months. I had backed out primers on once-fired brass in Winchester, Federal and Remington brass. I tried all types of powders in two rifles with the same results. I tried adjusting the die in and out. I reload for 5 other cartridges and have never had trouble adjusting the sizing dies right out of the box. I finally had enough and bought a set of Hornady dies and shot a couple of new factory rounds to get some brass to try and my problem is finally gone. No backed out primers. So I have around 75 casings now that I had sized with the Lyman die. If I continue to shoot them, will they eventually expand to normal size, or should I toss them? I have shot some of the bad brass and re-sized with the Hornady dies, but anything that previously was sized with the Lyman die will back the primer out, indicating that it has sized the brass too small. The primers are barely out of the casing, about .001" Keep the old brass, or toss it?