I guess you really should weigh your brass

QuietTexan

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I meant "before depriming" as in after firing and before decapping the case, whether you decap as a separate step or with a sizing die... so the primer would already be dead. Saves a step of plugging each case, and you're sorting at the expanded volume of the case before sizing.
 

BrentM

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I think the "weight sorting doesn't matter" logic relies on the assumption you're using cases from a single lot of brass that you have some kind of history on. Case capacity is more important then weight sorting inside a lot. If you have a bunch mixed you'd have to weight sort, then volume sort. If you haven't deprimed yet start checking some with water.

This right here. Weighing brass from same lot that is basically the same weight, plus or minus a grain or 2, is a waste of time. Sorting brass by weight that is 10 plus difference, different brands, etc, yep. I found 3 308 cases saturday on the mountain in a pile. All 3 different brands and 1 had a massive ejector mark. I mean so massive it has a piece of brass sticking up like a shard. Holy crap.
 

GrayCreed

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First time loading for 308. Got a pile of once fired Hornady Tap brass for pretty good price. Long story short. Spent over 300 rounds fighting 5 shot groups that had 3 and 2 together or 4 and a flier, cussing my chronograph, and scratching my head at random pressure signs showing up. Turns out Hornady changed their match brass at some point. I have some that weigh right at 160 gr. Some right at 172 gr. And a handful of regular head stamp Hornady at 190. All mixed together when tumbled and pulled back out in random batches. Go me.
Hornady once fired brass is really bad for this, I don't know if the Hornady bag brass is any different I started loading 6.5creedmoor with 100 pieces of S&B brass and 120 pieces of Hornady once fired brass from ammo I bought. Originally, being a newby I assumed that the Hornady brass would be best because they had a large online presence in the reloading and precision shooting community. I was wrong, not saying if you buy a bag of Hornady brass or bags all from the same lot you can't get good results. But after wieght sorting the brass I found that while the S&B brass had an extreme spread (brass wieght) of 3 grains and the Hornady brass had an extreme spread of 12 grains. While I know that internal volume and wieght don't always correlate, a variance of 12 grains either way (and this was not just outliers) most likely would have significant impact on my internal volume, groups and definitely velocity. I did figure out however that if you get Hornady brass all from the same lot it is very close to the same. The problem arises when you have 20 pieces from American whitetail, 30 pieces from 2 different boxes of Precision Hunter and 50 pieces of American Gunner.
 

ImBillT

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You really need to check capacity. Different brands of brass have different brass thickness so weight is a moot point. The best thing is to purchase good brass to begin with and you will have less fustration. There are some good posts on this forum to explain. Just do a search on Brass H2o capacity.
Your chamber has a fixed volume. Fill it with 160gr of brass(in any shape) and it’s volume is reduced. The very slight differences in density of different batches of cartridge brass is minuscule. For the purpose of this, the chamber ends as the base of the bullet, so the neck beyond that needs to be similar on all the cases being weighed. You’ll get good results if you have them all trimmed to the same length before weighing. You’ll get better results if the necks are all turned to the same thickness.

There is no reason to attempt to directly measure volume. It’s time consuming and prone to error from air bubbles and variance in menisci. An unfired case will have less volume than a fired case, but it expands to fill the chamber so easily that it has very little effect on pressure...only on how much powder you can fit in the case.

Weight sorting brass IS measuring volume. It’s measuring volume quickly, and accurately, and it’s better than filling your cases with water.
 
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Mike Matteson

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Somethings I do agree on: At lease case weigh your brass. Don't mix manufactures brass, at this point in time. I never tried mixing brass of different manufactures, and I won't either. Now I have change to purchasing better or top of the line brass or wait until I can purchase it.
The one thing is purchasing reloading items, is like pulling I-teeth presently.
Don't beat the man up, because he's doing something different. We all learn from our own mistakes, or if we get smarter by somebody else (if) mistakes.
 

Spoonbill

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Ive just bought my first Custom Rifle in .308 so I really appreciate this discussion. Just to through another question on the grill; What Standard Deviation in brass weight is acceptable??
 

Mike Matteson

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Your chamber has a fixed volume. Fill it with 160gr of brass(in any shape) and it’s volume is reduced. The very slight differences in density of different batches of cartridge brass is minuscule. For the purpose of this, the chamber ends as the base of the bullet, so the neck beyond that needs to be similar on all the cases being weighed. You’ll get good results if you have them all trimmed to the same length before weighing. You’ll get better results if the necks are all turned to the same thickness.

There is no reason to attempt to directly measure volume. It’s time consuming and prone to error from air bubbles and variance in menisci. An unfired case will have less volume than a fired case, but it expands to fill the chamber so easily that it has very little effect on pressure...only on how much powder you can fit in the case.
Yes it will take a lot of time to volume weigh the cases. You can go to "H20 brass on the internet. There quite a bit from Accurate Shooter about volume weight.
Now I haven't applied the volume weigh yet, but going to do so. I really want to see what can be achieve by doing that. If it doesn't come up much better, then back to only case weight.
I generally achieved about 1/2" groups in my reloading of my rifles, or fine that load that gets the 1/2" @ 100yds. I require of my rifles is about 3200fps with the 1/2" grouping. I've had those loads for years. Once I achieve that, I don't change that load. The reason for the 3200fps is the bullet flight is about the same in any rifle I use. So I don't have to rethink the path of the bullet in different yardage I shot from different rifle I shoot.
 

rbTanzan

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I have some 270 brass that differs between manufacturers by 20-25grains brass. The resulting loads differ by 50fps (3240/3290) and the high end is on the border of tolerating 'flat primers' but still accurate.
 
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