I trimmed some brass the other day and measured each case after trimming. I found that the trimmed brass was off by +.003 to -.005. The -.005 case came out in the middle of the batch (other than that one case it was +-.003) The lengths were not restricted to long at the beginning and short at the end, it varied on each case. I am using a Lyman manual trimmer. All of the primers were removed for the trimming and for the measurements. I am using remington brass. Does case length usually vary this much? Does the length of the case matter if there is no crimp on the bullets?