cdherman
Well-Known Member
This debate get raised intermittently and I kind of agree with several of the less than certain comments.
-- Brass does NOT always fully expand to the exterior dimensions of the chamber with the first firing. The statement by one or more posters that you have to do this with brass fired multiple times and only neck or minimal shoulder bumped is correct.
--- Weight of brass DOES correlate to the final interior H2O capacity of a case, once its been fired a couple times.
--- BUT and there is a big butt! I learned along the way that manufacturers admit that a lot of their weight variation is found in the base, and particularly, the extraction cut. So as much as the weight correlates with final interior capacity, it is NOT a perfect correlation.
--- Reloaders that have capacity tested entire lots of brass using H2O have reported no accuracy gains.
It is my OPINION the first and foremost thing you should do with brass sorting is make sure you are using brass from all the same lot from the same manufacturer. I have 2 lots of 6.5x55 Lapua from different decades. They have subtle differences in the headstamp. I would never mix them. I use them in different guns.
These days, I like to buy 200 rds of single lot brass, and weigh them. I arrange them in a nice bell curve. Sometimes you see quickly that the manufacturer has two machines going that are throwing a bimodal curve. Usually, I sort out a few extreme outliers and toss them. Thence forth, I do not worry about brass sorting ever again. How many? as few as zero or perhaps as many as 10. I strongly suspect I am wasting my time and precious brass, but I do it, seeking as little variation as possible.
This is not to take anything away from the OP research into the effects of first firing on brass/velocity etc. I think we all have known that first fired brass is not usually where a given gun gives its best accuracy/consistency.
-- Brass does NOT always fully expand to the exterior dimensions of the chamber with the first firing. The statement by one or more posters that you have to do this with brass fired multiple times and only neck or minimal shoulder bumped is correct.
--- Weight of brass DOES correlate to the final interior H2O capacity of a case, once its been fired a couple times.
--- BUT and there is a big butt! I learned along the way that manufacturers admit that a lot of their weight variation is found in the base, and particularly, the extraction cut. So as much as the weight correlates with final interior capacity, it is NOT a perfect correlation.
--- Reloaders that have capacity tested entire lots of brass using H2O have reported no accuracy gains.
It is my OPINION the first and foremost thing you should do with brass sorting is make sure you are using brass from all the same lot from the same manufacturer. I have 2 lots of 6.5x55 Lapua from different decades. They have subtle differences in the headstamp. I would never mix them. I use them in different guns.
These days, I like to buy 200 rds of single lot brass, and weigh them. I arrange them in a nice bell curve. Sometimes you see quickly that the manufacturer has two machines going that are throwing a bimodal curve. Usually, I sort out a few extreme outliers and toss them. Thence forth, I do not worry about brass sorting ever again. How many? as few as zero or perhaps as many as 10. I strongly suspect I am wasting my time and precious brass, but I do it, seeking as little variation as possible.
This is not to take anything away from the OP research into the effects of first firing on brass/velocity etc. I think we all have known that first fired brass is not usually where a given gun gives its best accuracy/consistency.
