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Old November 13, 2012, 06:55 PM   #1
rebs
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weighing cases ?

I had read a post about someone that weighs there LC brass for uniformity before reloading it. I gave it a try and was surpriosed to find a variation of 10 grains. Isn't that enough to cause variation in case capacity which would mean higher and lower pressures ?
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Old November 13, 2012, 07:08 PM   #2
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Yes, I'm using winchester brass find it very consistant in 308.
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Old November 13, 2012, 07:26 PM   #3
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If your a bench rest shooter yes. If your not no. Figure what percentage that is of the case weight. With my AR I can get groups under .700 with mixed brand brass at 100 yrds.
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Old November 13, 2012, 07:54 PM   #4
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Lotta hype over this subject.

If you're banging military brass out of an AR I think it's a waste of time to weight sort. You'll never be able to account for any difference in accuracy.

Differences in case weight are not always attributable to something that would affect case capacity, anyway- like a thicker neck.

I'm sure this is like every other subject like barrel break-in and cleaning that has no clear cut answer other than "it depends".

As a long range shooter I've researched this till my eyes hurt, and come to the conclusion that it mostly doesn't matter as much as other factors like load consistency and neck tension. So I spend my time on the stuff that I think really matters. I weigh cases, but don't sort. If I come across any that are out of "range", I just chuck 'em.
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Old November 13, 2012, 08:38 PM   #5
FrankenMauser
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For .30-06, 10 grains is a big spread.
For .308, 10 grains is pretty substantial. (About 5-6 grains, is the most you should see.)
For .223, 10 grains is massive.


Quote:
I weigh cases, but don't sort. If I come across any that are out of "range", I just chuck 'em.
I believe that qualifies as "sorting".
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Old November 13, 2012, 08:49 PM   #6
Bart B.
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A 1% spread in case weight's gonna produce better consistancy in load accuracy than the spread in flame and heat output across 100 primers or 100 exact charge weights of powder. Most folks knowledgable in internal ballistics feel wide spread in neck tension (release force needed on the bullet) causes a greater spread in muzzle velocity than the stuff mentioned above. Especially if you crimp (with any tool) case mouths into bullets.

Rebs, yes case with effects case capacity. Cartridge brass is uniform enough across all makes that a given cubic inch of it all weighs the same. Which means that a given case takes up so much of the volume in a chamber. Those with less weight take up less space. Their inside capacity is best determined (in my opinion) when peak pressure presses their bodies hard against the chamber wall.

Last edited by Bart B.; November 14, 2012 at 10:50 AM.
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Old November 14, 2012, 06:52 PM   #7
tobnpr
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Quote:
I believe that qualifies as "sorting".
Yeah, it does, doesn't it...

Just trying to make a distinction, I've read guys post about sorting cases by a couple tenths of a grain (talking like 7mm/.30 cal and up here) and then loading them separately, seeking differences in accuracy. I don't go to that extent, I just choose to lose the cases that are out of my "margin of error". To me, brass is cheap, for cripes sake. I spend $.30-$.40 per bullet, I'm not gonna worry about brass costs- it's the cheapest part of shooting. I can't help but shake my head when I read the lengths some guys go to trying to "not" buy new brass...

I've only got so much time to spend (or rather, willing to spend) on such pursuits. Being a realist, I know my best chance at ringing that 5" gong at 600 yards is time best spent elsewhere, other than certain things I view as inconsequential at the level I'm capable of shooting.

Once I saw a nondescript shooter consistently hit an egg at 600 yards with a nondescript rifle, and handloads he described as nothing out of the ordinary, I became a firm believer that nothing matters more than time driving the rifle.
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Old November 14, 2012, 07:19 PM   #8
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Quote:
I gave it a try and was surpriosed to find a variation of 10 grains
I have weighed a LOT of 223 brass and NEVER found even half that much variation. I would call the brass you weighed as very unusual.
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Old November 14, 2012, 08:21 PM   #9
Edward429451
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Me either, not in .223. Especially not of the same brand. I've gotten a 10 gr spread between different headstamps, but not the same headstamp. I suspect that you were weighing brass that was untrimmed, and perhaps a case or three of differing headstamp got mixed in your lot.
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Old November 14, 2012, 08:25 PM   #10
rebs
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The 10 grain spread I got is from LC brass of different date stamps and some of the same date stamp.
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Old November 14, 2012, 08:45 PM   #11
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There you go. May as well call them different headstamps and sort by year. Even with the same year, they could be from differing lots and be different. I'd sort by year and then weigh them, culling the wacked out weights. And trim them first to give some chance at uniformity.
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Old November 15, 2012, 06:45 AM   #12
rebs
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what I do is size and trim to length them weigh them, then I also weigh the bullets I am loading in them. Am I going through extra steps that I don't need to do by weighing cases and bullets ?
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Old November 15, 2012, 08:01 AM   #13
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Rebs, yes, I think you're going through extra steps that you don't need to do by weighing cases and bullets. Especially if you can't shoot your rifle and its ammo inside 1.5 inches at 100 yards all the time. You don't even have to weigh powder charges to get 1/4 inch groups at 100 yards from top quality rifles; benchresters don't weigh their charges for ranges 300 yards and less.

Last edited by Bart B.; November 15, 2012 at 06:43 PM.
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Old November 15, 2012, 10:52 AM   #14
F. Guffey
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I had read a post about someone that weighs there LC brass for uniformity before reloading it. I gave it a try and was surpriosed to find a variation of 10 grains. Isn't that enough to cause variation in case capacity which would mean higher and lower pressures ?




That is what happens when “I had read a post about someone that weighs there LC brass for uniformity before reloading it”, there is something called ‘rational’ or the reason why ‘someone’ weighed there LC brass. Then there is the ‘SHOCK’ to find all the weights do not match. In the responses you have you can see there are ‘sorta’ sorters, this stuff does not lock me up, nothing drives me to the curb. I purchased new, unfired, pull down cases from Houston, TX. and Pat’s reloading in Ohio. 4.000 total, why? I am a case former, nothing like forming cases that are new/unfired.

I am not a sorta sorter, I separate LC cases by weight, instead of acting like I was on twitter I do not run down the street yelling LC cases do not weigh the same, I sort my LC cases by weight, WHY? JIC, Just in Case it matters. JIC, the powder column of the military 30/06 is longer and smaller in diameter than the powder column of the 30/06 R-P case by .060”, no one on this forum or another reloading forum has acknowledge the diameter of the column and length of the column has an effect on or makes a difference when the trigger is pulled. They all believe the military case is thicker, that makes them half/right, for a column to be longer and larger in diameter the case head must be thinner, if the case is still heavier the weight must be in case body, SO, my 30/06 military brass has a thinner case head with a thicker case body, still heavier but not thicker in the case head and case body.

Then there is one of my rifles $120.00. 120 rounds, 6 boxes, 12 different loads, with 12 different case heads, 4 different bullets, 4 powders with different weights, new cases, once fired cases , commercial cases and military cases cases, etc., Groups only, no patterns.

There is sorting by head stamp, there is sorting by head stamp and date, there is sorting by weight, I am not a sorta separator, I can find difference between cases with the same head stamp, not a problem, I match cases by weight. Rational? Tumbling! I can tumble 120 cases, then spin/tumble in a case media separator and get all 20 cases back in the same box they started in.

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Old November 15, 2012, 02:46 PM   #15
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How timely is this thread ? Just this past week my partner and I went to the range and he was trying out some .223 loads in his custom Savage bolt rifle. The best he could do was 1 1/4 inch with this load . I checked his loads and saw that he had 4 different head stamps on his .223 military brass. All had been trimmed to length but not weighed or sorted. My partner could not believe this to be an issue so I gave him 20 of my sorted and weighed Lake City brass of the same year and we duplicated his load to the "T" with the cases being the only difference. We returned to the range 2 days later and fired groups measuring .725 inch. with a .010 further setback ( I take a Lee hand press to the range for this ) we got the rounds down to an honest .410 inch group. Maybe this isnt the case with all brass but you be the judge if it is worth the time and effort. I kinda like smaller groups therefore I try to buy larger lots of same run brass , process them all when they first arrive by running them through my FL sizing die, trim, uniform the pockets and deburr the flash holes then sort them by weight and put tags in the boxes showing their exact specs, give them a lot # and history as to times fired, sized, trimmed and so forth. OCD ? Maybe. I like to think anything worth doing is worth doing right the first time. If I dont do it right today I will just end up taking twice as much time to do it over tomorrow
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Old November 16, 2012, 10:31 AM   #16
tobnpr
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So, someone enlighten me, because I'm missing the point.

If sorting gives you some sort of "most accurate" range of weight for the brass... what do you do with all the others?

Load and shoot them anyway, even though they don't perform as well?

I just cannot see the logic in loading a case-at all- if I know it isn't going to shoot as well as the others.

Or, do you go through the time/trouble to develop a different load, for a different case weight....
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Old November 16, 2012, 11:52 AM   #17
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Quote:
If sorting gives you some sort of "most accurate" range of weight for the brass... what do you do with all the others?
It's range ammo. The box that gets handed to the friends to shoot while the perfect ones are for me. LOL>
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Old November 16, 2012, 12:31 PM   #18
F. Guffey
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“You don't even have to weigh powder charges to get 1/4 inch groups at 100 yards from top quality rifles; benchesters don't weigh their charges for ranges 300 yards and less”

Rebs, I would caution you against taking Bart B. seriously about weighing powder, for rifle there is a very narrow window between starting and maximum loads of 5 grains +/- very little, pistol is even less, and bench resters, always the bench rester. I was at the range when I was asked if I was a bench rester, I answered the question with a question, I ask “Do you know and understand what a Cajun NO! means”. Then my wife called and ask Dotty if she would have me call home, Dotty ask my wife if I was the bench rester, my wife responded with “When you see him from the back he looks handy, he passes as a plumber” my wife ask Dotty to tell me pull my pants up in the rear and then call her. From then on when someone ask dotty if I was a bench rester dotty would say answer with “NO” “But his wife says he is handy” and I had to explain to my wife what a bench rester was.

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Old November 16, 2012, 12:48 PM   #19
William T. Watts
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I sort by within 1gr, + or - .5gr is another way of saying it, I have thousands of Virgin and once fired cases, so yes I can sort cases into 1k round lots. Does it make a difference, can I shoot well enough to note the difference in group size, the best I can come up with is maybe.. That's enough for me to do what I do because I have the time, it's mine, I do what I want to do with it. William

Last edited by William T. Watts; November 16, 2012 at 12:50 PM. Reason: In this case pun intended, time is a factor (mine)
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Old November 16, 2012, 12:59 PM   #20
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I'm with William. I weigh sort cases to the same range that he does. I weigh powder charges, debur flash holes, ream primer pockets to the same depth and I turn necks. I just call it elimination of variables. Does my ammo shoot better because of it? I do believe so, though I haven't proven it to myself in quite a while and don't have that on the to-do list.

As for the weigh sorted cases that didn't qualify for what I'm loading right now, most of them qualified for a different weight range and are bagged and tagged for use later. The ones that were far out of range, either high or low, were tossed.
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Old November 16, 2012, 01:02 PM   #21
Edward429451
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Same here. I've loaded mixed brass in 223, and sorted and I don't think I can shoot well enough to tell the difference. But that doesn't mean that it doesn't help, just that I'm not a crack shot.

I weigh bullets for some loads at times. I can see a difference in weighing bullets, so perhaps I'm not too bad of a shot. If you've ever played around with Match bullets, you will see that the consistent weights are obviously an intrinsic part of what goes into a Match bullet, that makes it a Match bullet.

Last edited by Edward429451; November 17, 2012 at 10:03 AM.
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Old November 16, 2012, 02:14 PM   #22
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i sometimes weigh the cases for my .223/5.56mm show off loads. Most of my cases are LC and TW. A couple times i've run the numbers on 100 LC weighed cases. Both times the extreme spread was less than 2.5 and the standard deviation was less than one.

See tech then case weights:

http://ar15barrels.com/
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Old November 16, 2012, 09:15 PM   #23
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My understanding is that internal capacity will play more of a role in consistancy of loads and help keep ES/SD down and potentially better groups vs case weight. From my reading and experience it depends on the size case and manufacturer, whether weighing cases=uniform internal capacity.

I just did a little test last week with my fired 308 Win Winchester headstamp cases. Weighed cases for H20 capacity and then took the ones that had same internal volume and set them aside. Then after all was done went back and weighed those cases and found them to vay by as much as 3 grains in case weight for the same internal volume. So that shows me that I can not rely on case weight in this situation to give me uniformity.

But my interanl H20 capacity for all the cases I weighed did not vary more than 1.5gr anyways. So appear very uniform without having to weight sort
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Old November 16, 2012, 09:36 PM   #24
Bart B.
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Those believing that components need exact weights and prepping might want to call Sierra Bullets (1.800.223.8799) then ask how they get 1/4 moa at 200 yards with their best match bullets fired from unprepped & unweighed cases, metered charges and never work up a load with new lots of powder or primers; from full length sized cases in SAAMI spec chambers.

Note that all cases of the same weight will have the same volume when pressed to chamber dimensions at peak pressure. As they all don't have uniform wall thickness, how much out of round they are after shrinking down after firing, effects their volume and water capacity. As a case goes from perfectly round to more egg or oval shaped, there's less area inside for any body diameter. If the case is flat, it's capacity is zero.

Last edited by Bart B.; November 16, 2012 at 10:04 PM.
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Old November 16, 2012, 10:25 PM   #25
old roper
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This is clip from Sierra on how they test their bullets at 200yd no need to call just look at their site.

Sierra's experienced engineering staff maintains strict quality control throughout the manufacturing process. This includes in-line sampling, inspection at each major bullet assembly step, stringent manufacturing tolerances and accuracy firing tests.

Some of the most important quality control standards used are:
1. Weight Control of +/- 0.3 grain.
2. Jacket concentricity of .0000" to .0003" on target bullets and .0000" to .0006" on hunting bullets.
3. 100% final visual inspection for external defects.
4. Roving quality control inspectors perform other dimensional checks at the cupping, draw, trim and bullet assembly operations.

In order to accomplish accuracy firing tests, Sierra utilizes our 300 meter underground testing range daily. 200 yard accuracy evaluations are conducted on rifle bullets using a precision unrestricted machine rest. We also conduct daily 50 yard accuracy evaluations on our pistol bullets using a specially designed machine rest. If a group does not meet our high expectations, the production run is rejected. This rarely happens due to the quality control procedures that go into the manufacturing process itself. However, accuracy firing tests are still important to ensure that every bullet we ship is one we can be proud of.


I'm sure if we all had what Sierra uses we shoot small groups too as to the rest. When I was there they were using Hart barrels and they were going to run test for the 6.5x47 Lapua.

I should also mention Sierra does sell 2nd at a good price
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