1. Size - because you're going to lengthen brass in a FL sizing operation. That amount of lengthening will vary a little. The purpose of trimming is to get them withing spec and the same length.
2. Trim - just the most logical time to do this operation
3. Anneal - because sizing work hardens the brass. You are re-tempering the brass. If you size after, you are defeating the purpose of annealing.
Could you explain how annealing after sizing defeats the purpose?
It seems to me that annealing after you have work hardened by sizing makes more sense.
It really shouldn't make much difference if you anneal before or after sizing as long as you do it the same way every time for consistency.
