Weighing new brass

[User4302021]

exactly right. I did after many hours find a procedure that produces consistent and repeatable results. I took one case and prepped it as you suggested above including neck turning, flash hole cleaning, deburring, chamfering, once fired cleaned and polished.
Then I put a new primer in this one case. I filled the case with various powders, including salt and not one time did any of these materials repeat measurement. I took a flat used planer blade to pack and scrape the excess off. I also used a calibration weight and set it on the over filled case. None of these created the same measurement. I was off .1 to 1 grain.
So i took the case used a compressor to clean the case out and filled it with alcohol. Hard to find 200 proof/100% alcohol but it is out there.
Here is what I did to get the measurement to repeat -- exactly over 10 times. It works on other cases as well.
I filled with an eye dropper to the rim then I kept filling as the meniscus rose out of the case (concave with water as water likes itself more than teh case walls. Alcohol is exact opposite so a convex meniscus is the resultant) I kept adding one drop until it just spilled over the lip. A tissue soaked up the very small amount and my loading room is kept at a constant temperature as well so the alcohol evaporates quickly. So I have the procedure by empirical testing and data that is consistent and repeatable forrgot to mention. I would tare my scale with each case. Then put the case back on the scale an most of the time i was .5 grain high so I would blow the case out and it would tare. Then I built a spread sheet to log the results. An average deviation or standard deviation was not applicable although these results are on my spread sheet. I wrote my own formula using Max -Min function to get spread and set the alarm at .5 grain volume difference. Then I group the brass and use the one with the most cartridges and wait to populate the other groups.
I do have 100 cases of Lapua .338LM coming tomorrow. I will do the same on this brass with out firing just to see how close they are.

I know this is a lot of work. But i only load 100 rounds or so for hunting and use the rest on my own range. I can go out thousands of yards in my back yard. We live on a wheat ranch.

I hate using alcohol on a primer then loading the case to fire. I have an email into CCI to see if alcohol will ruin or negatively affect the ignition of the primer.

What scale were you using?

 

[Alex Wheeler]

Weighing brass is very important and for the most part it does correlate to internal volume. The problem with volume is its very difficult to measure it accurately and consistently. If your using Lapua cases you likely will not find enough difference to make much change, but weighing them to find an odd ball is worth while. I just weighed some Nosler 280ai not long ago. 4 grains from one lot to the next and it was worth 1 grain of powder to get back to the old speed. Take your 5 lightest and 5 heaviest and shoot them over a chrony to see for your self.

 

[J E Custom]

If I remember right I've had 3 in the course of loading tens of thousands of rounds and the last one was probably back in the early 90's.

In each case the only primer that went off was the one that got crushed. Even if the entire tray were to flash it should pose that big of an issue unless the loader is doing something really stupid like looking down into the case through the neck.

Yes, each one has considerable force but the tray cover doesn't have enough resistance to build any significant pressure before failing.

The only other weird thing I've had happen related to primers was once when I accidentally deprimed a live primer it went off. No damage, but it was an eye opening experience.

Novice reloaders really should find an NRA basic reloading class and take it if for no other reason than to get the safety aspects beaten into their heads instead of just winging it like most of us did. A lot of us had mentors to help us along the way but half or more of them weren't nearly as safety conscious as we need to be and we tend to mimick our mentors of course.

It's easier to learn it right from the start and always be safety conscious than it is to retroactively learn and correct ourselves as is true with most things in life.

I have always worried about de capping live primers and make it a habit to slowly push the primers out to minimize the impact.

As stated earlier, When volume testing I used live primers and the test media (Water or alcohol) contaminated them and I was not worried.
I once found some new brass that was already primed and didn't know how long they had been there so I tossed them in a can and added water to leave them safe for de-capping.

I had also heard that It was not wise to tumble or vibrate primed cases. (I guess someone had problems with explosions or contaminated them enough to alter there performance).

If anyone has heard of this please post. This has been a very informative post that should help all. It could also keep us older guys from winging it

J E CUSTOM

 

[Pdvdh]

Weighing brass is very important and for the most part it does correlate to internal volume. The problem with volume is its very difficult to measure it accurately and consistently. , ...but weighing them to find an odd ball is worth while.
Take your 5 lightest and 5 heaviest and shoot them over a chrony to see for your self.

Agree.
Been there and done that over the chrony.

I've weighed and kept records of 3,805 case weights of 223 Rem cases. The average case weight amongst the 23+ headstamped brands I've weighed is around 92gr.

The difference between the lightest and heaviest case weighed was 20.9gr. As Trump would say, UUuuuuge for a case capacity as small as the 223 Rem. [20.9gr/92gr]= 23% of the average case weight.

Within 36 casings of one specific head stamped brand, I found a 4.9gr difference between the lightest and heaviest case.

If you want to blow a primer in your AR15, mix multiple brands of cases together on your reloading bench. Develop a max load in the lightest brand of casing. Then use the same load in the heaviest brand of casings. Bye bye primer...

If there are any 223Rem aficionados (fans/reloaders) in the audience, I can provide my MS Excel spreadsheet. It prints out on 11x17" paper. Provides a range of 223 Rem case weights according to head stamps. PM me an e-mail address.

 

[Steve Sheasly]

Weighing brass is very important and for the most part it does correlate to internal volume. The problem with volume is its very difficult to measure it accurately and consistently. If your using Lapua cases you likely will not find enough difference to make much change, but weighing them to find an odd ball is worth while. I just weighed some Nosler 280ai not long ago. 4 grains from one lot to the next and it was worth 1 grain of powder to get back to the old speed. Take your 5 lightest and 5 heaviest and shoot them over a chrony to see for your self.

I just sorted 340 weatherby Nosler 50 rounds 1 grain spread
100 Lapuancases, 338 lapua magnum 4 grain spread
Hornady 50 cases in 338 LM 7 grain spread
Norma 50 cases in 338 LM 2 grain spread across all cases.

I have heard such great things about Lapua brass I bit the 3.00 per case price. Not that impressed the necks are out of round on some cases, there were metal shavings in the box and I was hoping for less spread. Nosler did extremely well.

 

[Pdvdh]

Nosler weight sorts their brass prior to packaging it for sale. Which is a nice effort. I hope your Nosler brass holds tight primer pockets at the pressures you expose them to. Some Nosler cases are soft. Some, like the 28 and 30 Nosler cartridge cases are reported to be pretty stout in their case head strengths. The consistency of case weight is nice, but that value is lost as soon as the primer pockets enlarge to the point they no longer seal off the gases from the bolt face.

The larger the physical size of the case, the greater the spread in individual case weights to be expected. And the larger the case capacity, the smaller the variance in MV per gr difference in case weight.

 

[Steve Sheasly]

Nosler weight sorts their brass prior to packaging it for sale. Which is a nice effort. I hope your Nosler brass holds tight primer pockets at the pressures you expose them to. Some Nosler cases are soft. Some, like the 28 and 30 Nosler cartridge cases are reported to be pretty stout in their case head strengths. The consistency of case weight is nice, but that value is lost as soon as the primer pockets enlarge to the point they no longer seal off the gases from the bolt face.

The larger the physical size of the case, the greater the spread in individual case weights to be expected. And the larger the case capacity, the smaller the variance in MV per gr difference in case weight.

First time with Lapis mainly hunting loads .I am thinking a 4 grain spread is ok

 

[Pdvdh]

First time with Lapis mainly hunting loads .I am thinking a 4 grain spread is ok

I had a 3.4gr spread across 100 Lapua Match grade 223 cases. Which seemed excessive for such a small capacity casing. In comparison, your 4gr spread over 100 338 Lapua cases, is quite good.

Considering the Lapua 223 cases average only 95.2gr, and their 338 cases average 333.2gr. My 100 338 Lapua brand cases had a maximum case weight spread of 6.4gr.

You should be tickled.

 

[Steve Sheasly]

I had a 3.4gr spread across 100 Lapua Match grade 223 cases. Which seemed excessive for such a small capacity casing. In comparison, your 4gr spread over 100 338 Lapua cases, is quite good.

Considering the Lapua 223 cases average only 95.2gr, and their 338 cases average 333.2gr. My 100 338 Lapua brand cases had a maximum case weight spread of 6.4gr.

You should be tickled.

Ye

 

[Alex Wheeler]

I just sorted 340 weatherby Nosler 50 rounds 1 grain spread
100 Lapuancases, 338 lapua magnum 4 grain spread
Hornady 50 cases in 338 LM 7 grain spread
Norma 50 cases in 338 LM 2 grain spread across all cases.

I have heard such great things about Lapua brass I bit the 3.00 per case price. Not that impressed the necks are out of round on some cases, there were metal shavings in the box and I was hoping for less spread. Nosler did extremely well.

I dont trust new brass. It doesnt shoot as well as properly re sized brass and tends to throw fliers.
You need to look at the variation in a %. What do those 338 cases weigh?

 

[Steve Sheasly]

1,

I dont trust new brass. It doesnt shoot as well as properly re sized brass and tends to throw fliers.
You need to look at the variation in a %. What do those 338 cases weigh?

1.4% between heavy and light .I develope loads with new brass and dial it in once fired. I hunt with once brass .Even though every says not,to .

 

[Alex Wheeler]

1.4% is not bad at all. Once fired is good to go.

 

[Steve Sheasly]

1.4% is not bad at all. Once fired is good to go.

I think I would draw the line at 3% would you agree

 

[Steve Sheasly]

I have always worried about de capping live primers and make it a habit to slowly push the primers out to minimize the impact.

As stated earlier, When volume testing I used live primers and the test media (Water or alcohol) contaminated them and I was not worried.
I once found some new brass that was already primed and didn't know how long they had been there so I tossed them in a can and added water to leave them safe for de-capping.

I had also heard that It was not wise to tumble or vibrate primed cases. (I guess someone had problems with explosions or contaminated them enough to alter there performance).

If anyone has heard of this please post. This has been a very informative post that should help all. It could also keep us older guys from winging it

J E CUSTOM

Well someone very close to me has tumbled lots of brass with primers in them not that I would recommend it but I've never seen a problem why the animal might make me a little more worried