About a year ago, I purchased a 6.5 - 300 Weatherby Mag. The gun is awesome to shoot and came with 200 pieces of brass and reloading dies. I was able to purchase 6 pounds of h870 powder which it loves. I am having a problem with the brass. The brass was supposedly shot 1 time. The brass has seperated on me twice and my smith said it is old brass. I need to buy some new brass or learn to form new brass. Can someone give me advice about forming the new brass. I am relatively new to reloading. Thanks in advance.