For those that separate and weigh their brass.. whats your tolerance?

[scythefwd]

Just curious.. I got a bit of virgin lapua brass in and separated it by weight. 84% of it was within .5 gr weight. a full 50% of it was .1 gr variance (either 173.7 or 173.8 gr)..

If you're actually keeping the brass together with the intent on eliminating all possible variances (also weighing projectiles, hand trickling charge to weight... ) how picky are you in regards to brass weight? .2 gr variance through the group, .5 gr? Just curious as to what you guys run here. My intent is to keep it all the same weight except when I need one to fill out my ladder for testing, then borrow form the group up.

So what do you guys do?

 

[Fine Figure of a Man]

I have a bunch of LC 308 brass that I sorted to .5gr.
A half grain tolerance may not be necessary but it shoots the same and lasts as long as my Lapua brass.

 

[LiveLife]

Isn't sorting by internal water volume better than sorting by brass weight?

 

[Demi-human]

Isn't sorting by internal water volume better than sorting by brass weight?

Yes. If one can shoot the difference. But one way is a lot easier to do than the other.

 

[ReloaderFred]

Weighing doesn't tell you where the variance is. It might be in wall thickness, in the web, the rim, etc. I stopped weighing cases a long time ago, but for accuracy I do still weigh bullets and powder charges.

Hope this helps.

Fred

 

[LiveLife]

Isn't sorting by internal water volume better than sorting by brass weight?

Yes. If one can shoot the difference. But one way is a lot easier to do than the other.

I thought OP was fairly clear in wanting to eliminate all possible variances ... which would include case volume capacity.

If you're actually keeping the brass together with the intent on eliminating all possible variances (also weighing projectiles, hand trickling charge to weight... ) how picky are you in regards to brass weight?

 

[hdwhit]

I segregate brass by headstamp, but I don't weigh it prior to reloading.

I do weigh loaded rounds (except 25 ACP where the variances are outside the sensitivity of the balance) against a standard weight and look for material variances that indicate something is amiss.

Every time I write that, I get a number of people posting that I'm foolish and wasting my time because weighing loaded rounds won't tell me anything. Well, 100% of the times I have had a round materially heavy or light, there has been a problem when it was disassembled.

 

[ray15]

Just curious.. I got a bit of virgin lapua brass in and separated it by weight. 84% of it was within .5 gr weight. a full 50% of it was .1 gr variance (either 173.7 or 173.8 gr)..

Looking at your situation numerically, 0.5gr. compared to 173.7 is only 0.2%. Pretty good brass, in my estimation. I can't help but wonder how much (or little) might be gained by cutting that variance in half, or even less.

 

[hdwhit]

bds wrote:
Isn't sorting by internal water volume better than sorting by brass weight?

I don't have an answer, but I am asking about technique.

If someone is going to determine the capacity of their brass by filling it with a quantity of water, how is this done? Specifically, I assume that the spent primer has to be left in the case in order to keep the water from running out of flash hole. If that is the case, how does someone ensure they don't have air trapped in the primer which is throwing their measurement off?

 

[Walkalong]

Weighing is much easier and is good enough.

 

[LiveLife]

If someone is going to determine the capacity of their brass by filling it with a quantity of water, how is this done? Specifically, I assume that the spent primer has to be left in the case in order to keep the water from running out of flash hole. If that is the case, how does someone ensure they don't have air trapped in the primer which is throwing their measurement off?

This is one way.

 

[Sunray]

Separating cases by weight or water volume won't and doesn't make a lick of difference. Unless you're a benchrest shooter. .1 of a grain even less of a difference.

 

[243winxb]

.3 gr.

 

[Laphroaig]

OK, here's my take on this.

I see a lot of people who weigh brass to arbitrary tolerances. Some are given in this thread, and were .3 and .5 grains. I remember once separating some .223 brass to +/- 1.0 gr. As was indicated, I assume we do this to ensure consistent case volumes which are sometimes reported as grains of water to fill the case.

Here's some numbers from a single 30-06 case that I weighed empty, then full:

Dry case with primer = 199.4 grs.
Filled with tap water = 268.9 grs.
Case volume = 69.5 grains

OK, lets assume that I want to separate my brass to keep the internal volume within 1%, or in this case 0.7 grs. Making the assumption that any variations to the internal volume will be reflected in the weight of the dry case, and considering the specific gravity of brass is about 8.5, then the case tolerance weight would be:

.7 * 8.5 = 5.95 gr.

YMMV depending on caliber and make of brass, but I think that there is more leeway than most shooters give.

I generally separate by headstamp and let it go at that. But I have seen some 30-06 weights that vary as much as 10 grs for a particular headstamp (HXP 70, for example)

 

[Laphroaig]

So if you weigh cases, and consider your time to be worth something buy Lapua or Norma and don't give case weight a second thought.

 

[murf]

Weighing is much easier and is good enough.

good enough for benchrest?

murf

 

[murf]

So if you weigh cases, and consider your time to be worth something buy Lapua or Norma and don't give case weight a second thought.

or starline!

murf

 

[murf]

I don't have an answer, but I am asking about technique.

If someone is going to determine the capacity of their brass by filling it with a quantity of water, how is this done? Specifically, I assume that the spent primer has to be left in the case in order to keep the water from running out of flash hole. If that is the case, how does someone ensure they don't have air trapped in the primer which is throwing their measurement off?

trapped where? i can't think of anywhere inside the primer cup a significant quantity of air could not escape.

murf

 

[murf]

Weighing doesn't tell you where the variance is. It might be in wall thickness, in the web, the rim, etc. I stopped weighing cases a long time ago, but for accuracy I do still weigh bullets and powder charges.

Hope this helps.

Fred

are bullet weight variances that bad? can you give an example(s) of how good, or bad? i'm serious here. i thought bullet manufacturers got rid of their weight problem a long time ago.

murf

 

[scythefwd]

murf, I've seen bullets half grain off. its not much, but it can theoretically effect things.. during load workup, I weigh projectiles as well. I also dont use a powder thrower for my loads. I use brass that has all been fired the same time.. Basically I want to remove as much variables as possible.. leaving the biggest variable the nut behind the trigger.. who as demonstrated to himself that he's capable of good, consistent groups most of the time.. all bets are off if I have taco bell

laphroaig - this is lapua

 

[murf]

murf, I've seen bullets half grain off. its not much, but it can theoretically effect things.. during load workup, I weigh projectiles as well. I also dont use a powder thrower for my loads. I use brass that has all been fired the same time.. Basically I want to remove as much variables as possible.. leaving the biggest variable the nut behind the trigger.. who as demonstrated to himself that he's capable of good, consistent groups most of the time.. all bets are off if I have taco bell

laphroaig - this is lapua

or a pot of coffee! scythefwd, i thought the "good" bullets had much tighter tolerances these days. half a grain is way too much for even varmint shooting. thx for the info.

murf

 

[Rule3]

Well I certainly hope that those cases are "surgically clean" and have no internal build up of anything on the interior surfaces.

As they are so clean I would use Lab grade pure H2O so as to not have any TDS in the test water. The dissolved solids could build up and cause a skew in the testing parameters!

 

[ants]

FYI

When Nosler uses water to determine case capacity, they fill to the bottom of the neck. Not the top.
Not saying you have to do this, just an FYI so it makes sense when you read their data.

No method is better or worse than any other if performed consistently and record keeping is thorough.

 

[Walkalong]

good enough for benchrest?

murf

Yes, everyone sorted brass by weight. Well, everybody I saw, and brass was also sold pre-prepped and sorted by weight for those who did not want to make their own 6PPC from .220 Russian.

 

[Walkalong]

So if you weigh cases, and consider your time to be worth something buy Lapua or Norma and don't give case weight a second thought.

Depends on how precise you want to be. Plenty of people buy many more Lapua cases than they need and sort them. I would make 100 6 PPC cases from 100 Lapua .220 Russian cases and then weigh and sort into small batches.