Weighing brass?

just did a batch of 50 casings from norma. I have a full 1.5 grs between ends. Generally, I weigh them and sort by weight just after sizing and trimming. I weigh the bullets as well. Not sure if it makes any difference, but I got the idea here on the forum a few years ago.
hardpan
 
I normally do not weigh and sort brass cases when I reload. I do occasionally weigh cases the first time that I buy a box of new brand cases when I get them to get some idea about a new company's product and how it compares to others that I use.

I kind of figure, at least with W-W case that, they are what they are. I have some higher expectation for Norma and for Nosler cases because they cost about 2x what normal retail cases cost. However, all of my rifles are either varmit or hunting rifles and as long as they continue to shoot MOA or better out to 300 yards and beyond (and better for the small bores) I am happy with the level of performance.

If I was going to shoot benchrest or competition at long yardage, I would weigh and sort cases. I would guess that I would measure case weights and look at range and distribution before deciding the number of weight range groups needed for sorting. It also might be a good exercise to take the cases from the two extremes that you find, load and shoot them in order to correlate group size with weight variation and compare that to sorted distribution groups of the closest weight distribution of cases that you find. If they are nearly the same, or there is little demonstrable difference, I would not bother with sorting.
 
I futilly weigh and sort Lapua brass. I sort into 20-round groups anyway, so I weigh them to sort. Typically I can get less than 0.3 or 0.4 grains difference per piece by sorting.

Futile.

I could use a concentricity gauge to sort brass. However, I think I'd end up getting it and realize the Lapua brass doesn't need to be sorted by neck thickness either, and it would be a waste of $80.
 
I weigh and sort, Remingtons and WW seem to vary the most. Nosler varies little. I have a 100 Federal match that also vary quite a bit, and have very rough primer flash holes.
 
wis - the only thing I load is a round for which brass is only made by Remington R-P. Case weights have varied between 213.0 and 218.4 grains.
 
I don't think weight sorting is going to give you the results you are looking for . case weight can vary , due to brass density , while case capacity stays the same . case capacity is what you are trying to sort . Jim
 
Jim, the only way to prove that is to fill the case with some media that fairly represents gas volume and then make sure that all the weigh media comes back out again in order to weigh accurately (not stuck in the primer). I suppose that sperical or short cut powder would probably be accurate enough to at least get a reasonably and directionally accurate sort for weight.

My guess is that the impact extrusion mandrels used to form the case to the finished inside dimensions are probably pretty consistantly machined and polished as they are made. Tool and Die makers usually are good about assuring that. That is why I do not normally weigh cases because that exercise does not give you the inside volume of the case, only the gross variation of weight in the wall of the case, mostly due to excentricity or TIR between the mandrels and exterior dies set and resulting wall thickness variation. In other words it is a set-up issue when the dies are made right. If a die/machine setter or mechanic wants concentric case walls, they will be so.

The reason that I say this is because people have been weighing cases since I started reloading almost 50 years ago and this is only part of the solution. Sometimes weighing helps grouping a lot, a little or not much at all. Why the variation in outcome? I think that this variabiity is something more complex than just inside case volume. That is why I mentioned set up and tooling.
 
Charlie , I'm sure not saying I'm right on this . LOL I have sorted by weight . I think a better way to sort is to use once fired , unsized brass .this brass should be all prepped and trimmed to length prior to firing . I think this brass will be about as true as you'll be able to get size wise . first weigh the brass . then fill the case with water and weigh it again . subtract the first weight from the second weight . this answer is case volume , or water weight . I think if brass is sorted by water weight you will get the results you are looking for .what's your thoughts on this approach to sorting ? thanks Jim
 
Jim

That's actually what I was going to suggest gives you a more accurate idea of what you have and fills the voids left by media or powder. I have noticed with the few Remington cases I have weighed that they can be up to 3 or 4 grains different. I was loading some rounds the one day and threw a loaded round on and then the next and the next I had a 4 grain spread. I was worried that I had screwed up so I pulled the bullets and weighed each charge. Each was right on the money kinda startled me how much deviation was in the brass.
 
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