I found some Remington small rifle primers at a LGS today but they are 71/2 bench rest primers. What is different about bench rest primers compared to normal small rifle primers like CCI 400? I want to use them in 223 for plinking. Are they softer than CCI? I have a lee press that says do not use Federal but CCI, Winchester and I hope Remington will be ok and not go Boom when seating the primers.