Brass sorting/weighing

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dasher john

Guest
Hello all-
I’m a newbie looking for your input on brass sorting/weighing. Here is what I have:
Lapua 6mm BR fire formed to 6mm Dasher and then reloaded/shot 1 time, neck turned, F/L sized, primer pockets cleaned up, trimmed to length and chamfered. I then weighed the cases and they varied from 124.5gn to 126.8gn with the vast majority coming in at 125.xgn range.
At this point what should I do next? Cull the ones outside of the 125.xgn range? I did a quick search of the forum and did find comments about brass sorting/weighing but nothing outlining a specific set of criterion.
Your input will be greatly appreciated. Thanks.

John
 
John,

Most people who weigh cases batch them i.e. separate them out into a number of weight bands. Without knowing the total number of cases you have, its hard to recommend how many batches you should create. You need to take into account how many "equal" cases you'll need at a time for the type of shooting you do.

An alternative to batching is sorting. I weigh the cases into a loading block (usually between 100 and 200) and record each one in a spreadsheet. Then I do a sort in the spreadsheet, and transfer the cases into another loading block in sorted order. I usually cull a few at the light and heavy ends because they tend to be spread more.

I then try to keep the cases in order both during reloading and at the range.

Alan
 
I then weighed the cases and they varied from 124.5gn to 126.8gn with the vast majority coming in at 125.xgn range.
At this point what should I do next?
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What you should do next is to see if there is any difference on target. That is, load up a couple of the 124.5 and a couple of 126.8 to make a set of cases with the most uneven weight. Use you normal loading techniques. Then load up five 125.x that have the smallest variation.

Shoot the groups at the distance you are interested in. Repeat a couple of times to get significant data. Are the groups essentially the same size? If so, you can stop weighing cases.

This works best when you have a companion to hand you the rounds, so you don't know what you are shooting. The mind is a powerful tool, and can "make" things happen.

As you can guess from my post, I don't think you can shoot a 2-grain difference in case weight, but my opinion and $1.50 or so will buy a cup of coffee. Find out for yourself.
 
I did an experiment several years ago to determine just how much effect brass weight has on .223 loads. I used WW brass (sized, trimmed and deburred, primer pockets uniformed, flash holes deburred, and neck turned) , WSR primers, charges of RL-15 or N-550 powder weighed to 0.1 gr, and 75 gr A-Max bullets. Using the lightest and heaviest cases (sorted from 1000 once-fired I had on hand), I had two lots of 10 cases with a 3 gr difference in weight. The average muzzle velocity difference was 16 fps, just a bit more than the 12 fps due to 0.1 gr of powder. I choose to sort 0.5 gr lots of brass for my long range loads, but the effect will only matter at 800-1000 yards - the vertical displacement on the target from such a small velocity change is negligible at shorter distances. Unless you control all other sources of variation, the effect of brass weight is negligible.
 
I did as you did, but as I weighed them I segregated them into 1/10th grain incraments. I then numbered them from 1 to 100, or 200, or whatever. Then I used one of those tools made for scribing into steel (the ones that have a sharp point and vibrate) and pemanatly numbered the brass....I shoot them in order.... So far I can easily identify each case after 3 firings.

I don't know if it makes a difference, but it sure can't hurt.

Good luck,
Tod
 
ronemus,

Good for you, you did the test and got your answer. I got a different answer, but at least neither of us blindly followed the advice from the "what some guy said" channel.

Factors that may have lead us to different conclusions is that the .223 is a pretty small case. Most of the cases I shoot hold between 55 and 90 grains of water. So if the weight variance you noted was all due to that portion of the brass that affects capacity (instead of from the base, rim, whatever), you can compute the variation in volume you've measured. Whether or not this will extend to cases of significantly different sizes would have to be tested. Yes, I'm aware my cases are also larger than the Dasher of the original poster.

My scale -- a Denver Instruments -- reads to .1 grains. Good scale. I figure it is theoretically accurate to +/- .05 grains (rounding). But what I really figure is it is accurate to +/- .1 grains (life).

I have, on occasion, held velocity variance in 5-shot groups to under 10 fps, but it is rate. Usually, my Extreme Spread is between 15 and 20 fps. I don't use Standard Deviation for the simple reason that it would take about 50 rounds to get a solid, statistically significant S.D. figure. I suppose it would also take that many rounds to get a statistically significant ES reading, too.

The hell with it. One of the reasons we tune our loads is to compensate for small velocity variations, even at 1,000 yards. Got vertical? Work on the load.

The only thing that really bothers me are people repeating some old tale they heard without testing, and then pronouncing it as true. That ain't you, you've done the work; I salute you.
 
Dasher John

John
Do a search of this forum for posts by Henry Childs.He buys 5000 cases at a time and sorts to the smallest weight his scale can achieve and keeps the biggest batch for himself and sells the others in weight sorted batches.He is an engineer by trade and knows his statistics as well or better than any poster on this forum.His info is rock solid and always backed up by credible testing.He would not do it if it wasn't of any value.
Lynn
 
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I can only afford 100 at a time and I weight sorted and numbered them with a acribe to shoot in order like you did. But my next batch of 6.5x47 will all be uniformed, trimmed fired once then double checked for any case stretch, re-trimmed if needed then sorted by actual water volume. A bigger PIA for sure but I will be sorting by what I see as the most important diffrence.
Larry
 
Thanks for the replies

Wow!
Some really interesting and thought provoking comments. Thanks guys.
For what it’s worth, here are my observations…
While I’m certainly not new to hand loading I am very new to the 1000 yard game. Heck I had never even squeezed off a 1000 yard shot until March of this year (thank you, Daryl Kopriva). Clearly, eliminating variables is the key. My train of thought dictates that in order to efficiently eliminate (actually minimize) variables one should first prioritize them. When I look at things just on the reloading bench alone, that need to be addressed such as bullet choice, bullet sorting, ojive and bearing surface measuring, meplat trimming, pointing, powder type, primer selection, primer weighing, seating depth, hard into the lands, jump to the lands, and the list goes on and on; it becomes evident that brass weighing will have to take a lower place on my list of priorities. Once consistently repeatable results begin to show on the targets, then I will focus on another one of the variables. If you tinker with to many things at once you cannot clearly determine if what you are doing is for the better or the worse.
Thanks to all for your input. I appreciate the advice.

John
 
john,
one of the reasons i do sort my weight( after most prep) is that i have the time to do it....plain and simple it is a variable, and i have the time.

mike in co
 
Here is another little "experiment" for you guys who weigh brass, esp. on large cases. Next time you turn necks, save the threads/chips you turn off. See just how much brass it takes to weigh .1 grains. To weigh 1 grain. That will give you a good visual idea of how much the case volume might vary (assuming the varying weight amongst cases isn't in the head, the rim, etc.). I did this. It sure disabused me of the notion that I could cc cases like cylinder heads. YMMV.
 
Lynn said:
J He is an engineer by trade and knows his statistics as well or better than any poster on this forum.His info is rock solid and always backed up by credible testing.He would not do it if it wasn't of any value.
Lynn
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He wouldn't do it if it wasn't of value to him. As in, arguably, a psychological edge. Confidence in one's equipment.

However, weight sorting brass has not been conclusively proven to help accuracy. It probably can't hurt. But there are too many variables for such a practice to be demonstrated as an improvement in scientifically valid terms.

The late, great Skip Otto fired a case once, when it was new. He, as a rule, did not reload. He figured, rightly for him, that there was WAY more benefit to spending time doing other things.

That's what makes it a horse race. Original poster, unless your time is unlimited, you'd do well to learn to read conditions if you want to shoot well at long range. One of the world's most accomplished long range shooters has seen match winning accuracy capability of conventional loads fired in an "improved" chamber -- while he's fireforming cases. What does that tell you? Don't go crazy with the little things. Unless it floats your boat.:D
 
There are some aspects of long long range shooting that I am not good at, reading conditions and taking the apropriate actions for those conditions, to name a few. But I can be a meticulus hand loader,i.e. be thorough and consistent. I haven't tried to prove that the following makes a difference:
I buy 500 pieces of Lapua brass all of the same lot (6.5x284) and weigh sort on table from lightest to heaviest to the .05 grain. Then I take out 13 for a Light Gun relay and 18 for a Heavy gun relay etc.Before placing them in a box for each relay I mark the base with red for record string and with black for best 3 sighters.. The remaining 5 stay unmarked. I keep a record of number of firings for this relay brass. I have the brass annealed after 4 firings.
My record string brass is numbered so for 1000yd shooting I can tell which one went out of the group. If that happens this piece of brass becomes an early sighter and I move one of the 3 best sighters into the record brass.
I am sure that consistent neck tension is the most important aspect of long range shooting.
 
I am sure that consistent neck tension is the most important aspect of long range shooting.
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I am sure the two most important physical aspects of long range shooting are (1) a good barrel, and (2) good bullets. Dave Tooley reverses that order.

I never worry much about neck tension. Occasionally I seat a bullet & it just plops in. That one becomes a sighter, but I can't prove it matters.

We all have our foibles. After I load my cases, I check the bullet runout. Ones with the lowest runout (< .001) are "match rounds."

Well, what's wrong with this? What's wrong is that I know Creighton Audette purposefully set down to see if this matters. He took 20 cases with little to no runout, and twenty cases where he physically pushed the bullet way off center (there goes even neck tension, too). Then he shot 2 twenty-shot groups. The groups were almost exactly the same size. Yes, he shot prone, at 200 yards. But then, he was Mr. Audette and we're not.

So I know what I do is silly. But many of us need something to let our psyches feel we've done something special, even when we haven't.

I'm still looking for something that really matters, so I can do something useful whilst easing my psyche. I think it is case necks, which, when done right, do give even tension. But it isn't *just* about tension. And no, I don't usually measure bullets, or weight them, either. *Good* bullets mean ones that don't vary, within a lot, or over lots. (Now, BIBs are good bullets, and no, I have no financial interest in them.)

All I'm saying is be honest with yourself. Test, abandon the fruitless, and retest as you reach another shooting plateau. Maybe your test failed because you're a rotten shot. If so, when you get better, you'll have to restest.

And remember, some things come in twos: doing just one is of no benefit, doing the other is of no benefit, but doing both in concert is. You still have to prove it, of course, like T.J. Jackson did in the warehouse by both boring case necks true to the bore centerline *and* squaring the case head. One's of little value without the other.

Well, to be honest, what he proved is that a 5 cases with .010 variation in wall thickness, after being bored & squared, shot as well as cases without such a "defect." Both groups were solidly in the zeros. That's slightly different than saying you have to do it for all cases.
 
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How it goes

A fellow will weigh cases and shoot better next time out. For him, weighing cases just moved up the good list. When he later shoots poorly with those same cases, he doesn't change his list back.
 
Bill Ohio

Bill
I seriously doubt someone like Henry does it to feel all warm and snugly about himself.He does nothing without a purpose.
In the longrangre game the worst 6BR case spread will be 125 grains to 128 grains which is well under 1 percent exteme spread.
If you look at 300 Weatherby brass made by the various vendors it will run from a low of 212 grains to almost 300 grains.That 90 grain difference between vendors is equal to roughly 4 grains of powder charge.Simple math will let you decide from there how much variance YOU can live with in your loads.
If you take the time to weigh your powder charges,bullets weight and primers you should know what your loaded rounds will weigh as well.In the case of the 6BR it looks something like this 127+105+31.5+3.8= 267.3 grains for a loaded round.
On a 300 Ackley it looks more like this but is brass manufacturer dependant.268+210+75.5+5.3=558.8 grains for a loaded round.
For safety sake you can check your loaded rounds and any variance is an error.
Lynn
 
seriously doubt someone like Henry does it to feel all warm and snugly about himself.He does nothing without a purpose.
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Yes, "warm and snuggly" gives a connotation that doesn't fit Henry. He's a good guy, but not "warm & snuggly." He is an engineer -- and a damn good one. He knows that variations in case volume do, on a "clinical" basis, result in a variation of pressure, hence velocity, hence bullet strike. If you're a good enough engineer like Henry, you can even compute the value.

Now, I like Henry. More to the point, I've shot against him. That "against" matters. We're competing, and for those 16 minutes, I want to beat him. When we're on the line and I sit down with my unweighed cases, and he sits with his weighed cases, I have no worries. This is based on experience, but it isn't "clinical" data. It is "shooting over time in competition" data.

It does no harm to weigh cases. The only harm is putting too much emphasis on it, that is, when you don't shoot well, going back and re-sorting cases in an even finer weight group. It does harm because that wasn't the problem.
 
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first we have to remember we are on the 600/1000 yd forum, not the short range forum. a little does make a difference. i dont have enough experience with the small 6 cases to comment, but when one moves up in case size there are big differences. i have done a bit of work with both 7 rem mag and 300 win mag. every manufacture has thier own formula for how much brass goes into one case and with in one manufacture there are noticable case volume variations.
we would not consider shooting bullets with a half grain variation, why shoot cases with 2-3-4 grain variations ?

so apply some smarts, based on the size of cases you shoot and your comfort zone.
back to the small case stuff..i have from one lot of 500 win 223, 30 cases that after full prep weigh the same. when i shoot these cases, i know the case is not a variable.( and for those that just must know,,,the cases were checked for volume...yep they match)

mike in co
 
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You said it best,if they weigh the same that is not a variable!
 
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