Lc brass Differences over the years

[freonr22]

Ok I used the cgn google search, and also just read through 10 pages of reloading section search for LC Brass.

I have some older (LC 69-78) brass and newer (LC 02-07) brass. Is one more desirable than the other? they are all once fired.

But if you were going to trade some which one would you keep and why? Is the newer stuff lighter duty because they are cranking out 1.6 billion a year vs the old school non computer way?

Or is high tech doing a more consistant job? thanks for your time

[ocabj]

I tried weighing 90s LC versus 00s LC but there wasn't really any consistent difference.

Though for some reason, early 90s LC seems thicker than 00s LC. But again, the weight differences weren't consistent.

[freonr22]

stupid question, I see some people weigh their cases... Why does that matter? I could see a volume difference mattering, but why sort the cases by weight? and if you did, what adjustments would you make?

[CSACANNONEER]

The case volume is almost dirrectly proportional to the case weight. I know one person who actually measure the case volume of ever piece of brass. He has weighed them too and finds that weighing gives him almost identical results. He's just very anal and won't stop measureing the volume of each case as well.

[ar15barrels]

stupid question, I see some people weigh their cases... Why does that matter? I could see a volume difference mattering, but why sort the cases by weight? and if you did, what adjustments would you make?

When fired, in the same chamber, each case expands to fill the chamber.
Therefore, the external dimensions are the same.
So if your cases weigh the same and the outside dimensions are the same and the brass density is the same, it stands to reason that your remaining case volume would also be the same.
Differences in brass density make much smaller changes in case volume than they do in weight so sorting cases by weight is a very good way to know that they all have similar case volume.

[Sheldon]

Wasn't I reading, at some point when Federal, or whoever the parent company is, took over the LC plant that brass started to become more like Federal (soft) than the harder LC stuff....?

[freonr22]

Thank You Randall! I understand it now. So is there any advantage to lc04 or lc69? ie older vs newer?

[ar15barrels]

So is there any advantage to lc04 or lc69? ie older vs newer?

69 pleases everyone.

[freonr22]

Ha Randall. Ok I only grabbed one of each,,, there are more years not sorted
lc69 98.6 grains
Lc73 93.1
Lc04 94.8
Lc05 95.6
Lc06 96.7

is this enough of a representation? or really should they be sorted by year?

[ar15barrels]

Ha Randall. Ok I only grabbed one of each,,, there are more years not sorted
lc69 98.6 grains
Lc73 93.1
Lc04 94.8
Lc05 95.6
Lc06 96.7

is this enough of a representation? or really should they be sorted by year?

measure 10-20 of each year.
Drop them into this spreadsheet:

https://www.ar15barrels.com/data/223weights.xls

PM me the raw data strings and I will add it to my spreadsheet.

[freonr22]

soo awesome! thank you. I will weigh them shortly. ps headstamps mal? also tw or tww?

[ar15barrels]

soo awesome! thank you. I will weigh them shortly.

One of these days, I'm going to solid model a cartridge that's blown out to chamber dimension and figure out what a solid brass chamber would weigh.
Then I can formulate the case volume of a case by subtracting actual case weight from theoretical solid weight to leave a remaining weight of brass that gets converted into a volume of space.
Taking it a step further, we can also look at the difference that 223 vs 5.56 chambers make to the same round of ammo.

[Technical Ted]

One of these days, I'm going to solid model a cartridge that's blown out to chamber dimension and figure out what a solid brass chamber would weigh.

As long as this modeling doesn't involve you in a bikini, we're cool.

[freonr22]

oops i will retract the weights as the spent primer are still in... i will reweigh

[ar15barrels]

oops i will retract the weights as the spent primer are still in... i will reweigh

If you read my notes, my case weights ALSO include a spent primer.