You should only need to trim to length once in a bolt gun, mabey twice over the life of the cgt in an AR. I always shoot new brass prior to trim to length. Gets it all streached out to my chamber. For once fired brass, I will full length resize, shoot and then trim. I tend to only neck size after that. Even in my AR I only full length resize every 4th or so shooting. The necks last longer, and of course annealing helps, but that is another story.
Tom
