I recently bought two boxes of Lapua brass, both are the same lot number. Can I mix those two boxes of brass together and make it a 200 piece batch without it affecting accuracy at tournaments?
Mixing brass of the same lot number
- Thread starter TackDriv3r
- Start date
I guess it depends on your level of shooting skill.
Can you tell the difference in unsorted Lapua brass?
Can you tell the difference in unsorted Lapua brass?
That is what I do, and break them into 50 round "batches" based on the weight sort. Only a little time on my part.
Dimner
I do believe in Captain Crunch.
Has any one been able to view the brass coming off the line and being boxed? If it's all the same lot# and it's randomly picked to be boxed, having a 100 or having 200 is probably going to be the same. If I were really worried about brass of the same lot, I would either sort when fireforming or sort by volume. Either way though, I could never shoot the difference.
7br
Silver $$ Contributor
Ditto bugman and jepp2. I do the same with excellent results. Lately I’ve been getting tighter weight variance with Peterson brass over Lapua. Your mileage may vary. I know some guys rely on water volume. I’ve never done that but they seem to get good results with that method.
Chaotik
Gold $$ Contributor
I have not tested this, but am considering mixing 2 boxes of different lots of Lapua brass and then volume sorting them, either water weighing or using the Bison Armory case volume gauge. This is specifically for LR benchrest competition.
I typically just volume sort brass from the same lot.
I typically just volume sort brass from the same lot.
Sort the brass before firing? One box is still unopened, I have already fired about 60 cases, labeled them as fired 1X on the other box. Sheesh
Might as well shoot the remaining cases, and dry weight sort all 100 fired cases with the spent primers in, I don't think the spent primers won't matter since we use the H20 method with the fired primers intact, right?
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I understand, but my matches requires 60 rounds for 3 matches for one event. May have to sort 100 pieces
two boxes of Lapua brass, both are the same lot number.
Those 200 pieces of brass with the same lot #? Isn't that by definition a 200 piece lot? I wonder what the plant calls a lot, a million or more? Wish I had a "lot" !
Frank
Those 200 pieces of brass with the same lot #? Isn't that by definition a 200 piece lot? I wonder what the plant calls a lot, a million or more? Wish I had a "lot" !
Frank
jackieschmidt
Gold $$ Contributor
I have Lapua 220 Russian and 6BR brass that varies in several years of manufacture. I cannot tell them apart.
In 6BR, there is a slight difference in the neck wall thickness that came about when they dropped the old gold card board box for the blue plastic box.
The fact is, I have never paid any attention to the “lot numbers” of Lapua cases.
In 6BR, there is a slight difference in the neck wall thickness that came about when they dropped the old gold card board box for the blue plastic box.
The fact is, I have never paid any attention to the “lot numbers” of Lapua cases.
Would you know if the " blue box " neck wall thickness is thinner than the old cardboard brass?
Both boxes were probably made from the same pile of brass at the factory. Maybe thousands of cases in a big pile gettig boxed.
It’s the same lot
Number. Mix them all together
Number. Mix them all together
Ned Ludd
Silver $$ Contributor
They're the same Lot#. You're not likely to get brass any more consistent than a single Lot# without adding sorting steps of some kind. If you're seriously worried that the brass in one box from a specific Lot# is somehow markedly different than the brass in another box with the exact same Lot#, I would suggest sorting all of the brass into 200 groups of one piece each. You won't get any better consistency than that. 
searcher
Gold $$ Contributor
I do not know this for fact - but I assume a lot number is changed any time there is an adjustment to the equipment running the line or a change in the brass lot used to form the brass. From the beginning of a lot to the end of the lot run, there would be expected minor difference due to slight calibration changes due to wear, etc. I have measured a lot of Lapua brass, and I have only learned that the difference from one lot to another may not override the differences found within a given lot. So, I just weigh and measure all brass into lots - whether from the same lot or not. I have taken 1,000 Lake City once-fired cases of three or four production YEARS. After weight sorting into three groups, turning necks, pockets, flash holes, etc. - they shoot so well that I have not gotten better groups using Lapua 223 match brass that was not weight sorted or otherwise prepped for accuracy. That is not a knock on Lapua - just an illustration that there were certainly brass material changes made plenty of times, machinery adjustments - and running on different machines with that Lake City and sorting works. I'd not worry about mixing those boxes up - but I'd still sort them.
jackieschmidt
Gold $$ Contributor
All I know of is 220 Russian and 6BR.
When measuring with a Ball Micrometer, both are thinner by about .0005 when going from the earlier cases to the new.
I have three new boxes of Lapua 6BR that I am using in my no neck turn 6BRA, (.272 neck), and the neck wall is very consistent in thickness. Some of the best I have seen. The wall thickness is an average .0124.
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Dimner
I do believe in Captain Crunch.
Jackie, your post reminds me... something I keep forgetting about. This may help out other amateurs like me.
I really don't have enough confidence in my mic skills to trust anything other than the thousands place. or maybe being able to tell if it's above or below .0005. I have the mic with the clutch, and I use a mic vise. I will spin a piece of brass that I have marked off in quadrants on the neck. Each quadrant labeled A,B,C,D. After rotating 360, when I get back to the same letter, lets say C, it will often be +/-.0001 or even +/-.0002 from the measurement before.
I'm using the Shars tube mic from 21st century. I'm not sure if that is part of the problem, or maybe the clutch? However, I suspect that an experienced fella could do just fine with it or 21st cen wouldn't be selling them.
The bottom line is, until I can afford a very consistent neck turning setup, I continue to lack confidence in my readings. I'm hoping that when I get my neck turning setup, and do some skim turn tests, I will be able to re-measure and possibly get a better idea of what I need to do to get more consistent readings.
Dimner
I do believe in Captain Crunch.
would you mind telling us more about that?
Do you do it with specific bullets, is it already fired brass?
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