They having said that do have non-uniform lengths. If you do not trust me, have a batch of brass with exactly the same headstamp and evaluate their lengths - I have measured hundreds, they are doing as being a fact differ in duration. With all the FC brass I measured, https://9mm-dirty-once-fired-bras31852.shotblogs.com/indicators-on-9mm-brass-for-sale-you-should-know-50767940