Alpha 6 BRA - CC Vs Weight

[bikemutt]

Jerry, I will say I felt better about the results I started to get when I tried Dave's mention of using upside down spent primers to make the seal. I don't feel the love with the 21st Century plugs.

[jvw2008]

I used to use the spent primers and then switched to the plug. Feel like I get equally good results with both. I did find it is important to dry the plug between cases.

[jvw2008]

"As I do more of this type investigation, the more I'm feeling that the need to sort may actually be most dependent on what brass manufacturer you are using."  my Post #13 in the Case capacity measurement thread started by bikemutt

As described earlier in this thread, I assayed the correlation between dry case weight and water case capacity in a recent batch of virgin Alpha 6 BRA brass. Over a 0.9 gr range in dry weight, there was only a 0.01 H20 gr variance in case capacity. Based on prior assays I've done with Hornady, Norma, Lapua, and Nosler brass, this amazing consistency in this lot of Alpha brass case capacity is just not something you would expect to see. It is also not what is reported in older reports from other reloaders when reporting results from non-Alpha brass.
I'm a bit paranoid about reporting information that is not correct or even misleading. So .... ? I went back and repeated the above described procedure. I won't bore you with the numbers - my results were the essentially the same.  I fumed over this for a day or so and ended up calling a friend at Alpha to get their opinion. The rep's answer was:  "yep, your numbers are about what we would expect".  Here is why:

Large brass producing firms like Hornady or Lapua will run 5-6 different tooling lines simultaneously while shucking out a couple hundred thousand cases in a 24 hour run. Each tooling line uses a different set of dies for the cartridge being run and there is very little time to shut the line down for quality control checks. All 5-6 lines are producing the same cartridge case, but each line is using its own set of tooling dies which will not be exactly the same.  Because each line has its own individual set of dies, each line will produce a slightly different case compared to the other lines.  They may produce, in one day, the number of cases that Alpha would require two weeks to produce. Alpha uses a much slower process utilizing one line with the same set of dies from the first to the last case produced in any particular lot. They describe this a single die tooling system. You have probably heard the term a "single tooling" system which usually refers to cutting during machining. Alpha is intentionally running a single set of dies. Running a single line and not running it 24 hours around the clock allows Alpha to do frequent QC checks and to produce brass that doesn't have the inherent variability of brass coming from multiple lines with different die sets.  "Single die tooling" is the answer (IMO) to the reason that the benefit of capacity sorting may be
manufacturer dependent.

[gman47564]

That makes sense jerry.. i wonder if the other manufacturers run all their lines in a big bin and then box them up.. sounds like they might..

[jvw2008]

Yes I'm pretty sure they do.

[Ranger 188]

Jerry, that's what I've been told also.
They have one set of die's and one press to make a run of one particular case.
That's why it's really expensive to start a new case.
(been told $100,000 )

[jvw2008]

Think there are several dies required to shape a case but the idea is the same - they use just one set of dies, beginning to end.

[bikemutt]

To some extent it depends on what each manufacturer means when they assign lot numbers to brass. If they are running multiple lines, and each line is assigned a different lot number, that dials out the tooling die variable. If all the lines lead to a big bin and the bin is assigned a lot number, that would explain tooling variances.

The only way to know I guess, is to ask each manufacturer how they do it.

No matter what, equipment wears out, there's still going to be a difference between widget #1 and widget #1,000,000. That's where tolerances and QC kick in.

[jvw2008]

The larger manufacturers who run multiple simultaneous lines are not going to find it cost effective to process the product from each line separately. Many of the production steps involve short inspections and quick individual steps. Don't think they would hire additional QC inspectors for each individual line, or set up multiple flash hole punch machines for each line.

I see Alpha's brass production approach analogous to that of custom hand drawn bullets versus Lapua's brass production as analogous to Berger mass production of bullets.

[bikemutt]

Lot number granularity is up to the manufacturer, it all depends what benefit they hope to derive. Clearly lot numbers are vital in the healthcare and food supply industries where lives may be at stake, or the product is perishable. Some ammo components, and finished ammo manufacturers no doubt depend on lot numbers for safety recalls and the like. I don't know if brass would really warrant lot number tracking, it might though if case heads separated on the first firing

In any event, lot numbers are free, if I was the brass company's king, I'd decree that each line has it's own series of lot numbers It might make me a broke king, but I'd sleep better at night