Tell me I'm doing the right thing

[BJung]

I sort by H20 capacity only after 3rd fire forming, before any sizing.
That's what I load develop with.
After development, When I get a flyer, I toss the case.

It's not about weight at all, and not even directly about static volume.
It's about brass energy to reach chamber wall (dynamic volume).
If you measure & match capacities of chamber formed brass, FL size them, and re-measure capacities, you're likely to find a few leaving the pack. That sizing is adding energy for the brass to accept this or that much of. As the brass acts differently to sizing, it will act to expansion on firing.
Then if you FL size enough to need trimming, capacities are changing again. And if you change your annealing from case to case or as developed, you're affecting brass energy.
The more you do to matched cases, the faster they no longer match.

In reality, it takes more than effort to manage matched energies. You can't viably hold it with just effort.
Instead, it takes a specific plan to do so.
Part of that plan would include tossing the bastards.. Don't waste another shot from one.

What are you doing before volume sorting and before the 3rd Fire form, weight sort? Do you sort by concentricity?

 

[BJung]

Really? During a benchrest match? Cuz' my question was asked in regard to that realm. Just asking.

I'm assuming you're a benchrest shooter. I have a different question and will start a new thread.

 

[hoz53]

I need to ask a sincere question and this is not to start a pissing contest:

If powder charges are thrown without weighing to the kernel (as in most tabletop shooting) why be concerned about fractional differences in brass capacity?

Jeeeez I hope this doesn't start another pissing contest...

short range BR shooters throw from a measure-(not all). the long range guys are the ones that are concerned about case capacity and many weigh to the kernal

 

[hoz53]

I meant to say, has anyone compared test loads with the powder charge that was weighed with a trickler vs. test loads where the powder thrower was adjusted to throw a certain volume/weight and the powder just thrown afterwards. Did I read correctly that benchrest shooters do this?

many many people have done this over many many years in the past. youll have to do it if you want to find out the specifics for your situation.

 

[Dusty Stevens]

I meant to say, has anyone compared test loads with the powder charge that was weighed with a trickler vs. test loads where the powder thrower was adjusted to throw a certain volume/weight and the powder just thrown afterwards. Did I read correctly that benchrest shooters do this?

Yes benchrest shooters do this

 

[Ray123]

I'm loading 300 cases of Lake City brass, just sized, trimmed, and champhered. For a AR 10 but sometimes bolt gun. No further prep ever ...same with Lapua brass, or Alpha brass...sometimes the AR 10 or 15 shoots these LC brass cases filled with what it likes with 10 shots into less than an inch...the 6 dsaher Alpha brass wasn't weigh sorted but it shot 13- 5 shot test groups with different bullets and powder charges into and average of .313" at one hundred yds for 13 groups tested that day. So I don't weight sort, neck turn, uniform primer pockets, or sort bullets, etc. An AR 15, 300 Hamr can shoot 150 Speer BT 2400 fps onto a 1/4" 5 shots sometimes, with crap mixed brass and bullets...or 5.56 AR 12 shots into one hole less than an inch mixed brass, 40 gr Nosler BT 8 twist... shouldn't work but it does. IF a barrel likes what you feed it, a good barrel will shoot good...much of this loaded on one of the Dillon progressives... Unless you into very serious competition no need to fuss over the small details. Shooting is much more fun than weight sorting brass. Don't fret the small stuff...unless you want to ... then by all means...go ahead, its your time, and your dime. By the way a couple of days ago to get the brass i am now reloading, which was Lake City with live LC primers, and dirty, with bullet sealent, so I buffed off the bullet sealant but left it on the case body, then neck sized the case neck only, and loaded them in the Dillion with the old W 748 I got for $14 / pd and 15 cent bulk 130 Speer Varmint bullets. This blasting ammo, shot 5 shots ino .374".. luck? The next 5 into .45 " the AR 10 liked crappy, dirty ammo, fun, cheap, accurate blasting ammo... Couldn't have planned it that well.

 

[mikecr]

What are you doing before volume sorting and before the 3rd Fire form, weight sort? Do you sort by concentricity?

For early sorting I check every case for thickness and thickness variance at mid-necks.
I need every case to match as manufactured. I'll lose a bunch there.
After fire forming and H20 capacity checks, I typically keep the tightest 2/3 of that.
My brass will last forever, and I only need around 50 for use anyway, so I'm not bothered by any of this.

 

[BJung]

I sorta gotcha. You neck size and expand with a mandrel first to measure neck thickness. How much variation are you looking at? +/- .0002" for a certain common thickness or do you draw from one large lot that forms a bell curve, culling out the tail ends? Do you neck size here? Do you mark the thick point on the brass body?Then, you FL size and fireform. And last you measure the volume. Do you keep the spent primer in or extract the primer and use a plug for the primer hole? Have you used rubbing alcohol? How do you ensure all the water is removed? Do you lay the brass in the sun?

 

[BJung]

I'm loading 300 cases of Lake City brass, just sized, trimmed, and champhered. For a AR 10 but sometimes bolt gun. No further prep ever ...same with Lapua brass, or Alpha brass...sometimes the AR 10 or 15 shoots these LC brass cases filled with what it likes with 10 shots into less than an inch...the 6 dsaher Alpha brass wasn't weigh sorted but it shot 13- 5 shot test groups with different bullets and powder charges into and average of .313" at one hundred yds for 13 groups tested that day. So I don't weight sort, neck turn, uniform primer pockets, or sort bullets, etc. An AR 15, 300 Hamr can shoot 150 Speer BT 2400 fps onto a 1/4" 5 shots sometimes, with crap mixed brass and bullets...or 5.56 AR 12 shots into one hole less than an inch mixed brass, 40 gr Nosler BT 8 twist... shouldn't work but it does. IF a barrel likes what you feed it, a good barrel will shoot good...much of this loaded on one of the Dillon progressives... Unless you into very serious competition no need to fuss over the small details. Shooting is much more fun than weight sorting brass. Don't fret the small stuff...unless you want to ... then by all means...go ahead, its your time, and your dime. By the way a couple of days ago to get the brass i am now reloading, which was Lake City with live LC primers, and dirty, with bullet sealent, so I buffed off the bullet sealant but left it on the case body, then neck sized the case neck only, and loaded them in the Dillion with the old W 748 I got for $14 / pd and 15 cent bulk 130 Speer Varmint bullets. This blasting ammo, shot 5 shots ino .374".. luck? The next 5 into .45 " the AR 10 liked crappy, dirty ammo, fun, cheap, accurate blasting ammo... Couldn't have planned it that well.

Lapua brass are good. I once acquired random assortment of Lapua picked up from a range and the brass I had was more consistent than the American brass. I've read that LC brass is consistent but never weight separated my lots to compare. And I never ran across Alpha brass. The brass I use are range brass. I picked up a lot so I can afford to cull out those that are not consistent like Lapua. I plan to assemble loads with random weighed brass and bullets later to compare those groups to a highly refined load someday. I'm just not there yet.

 

[NorCalMikie]

"Had" a good shooting buddy that got that involved with building his ammo.
Kept written notes of every round he ever fired in each of his rigs. Temp, wind, bullet, brass, powder and anything else that he thought of.
While he was taking notes, I had burned off 20 rounds (all going in the same hole) and was reloading. He had his style and I had mine.
A brother from another Mother. I miss him.

 

[mikecr]

Lapua brass are good.

Fixating on brass brand can be a mistake.
I've seen both the best and the worst brass to cross my bench, in Lapua 6BR.
Truly, if off-the-shelf consistency was my only goal, I would go with Norma.
But brass life is a long term part of consistency, and for that I used to go with brown box Lapua, and pick out the diamonds in the rough. I don't know how good blue box is..

 

[mikecr]

You neck size and expand with a mandrel first to measure neck thickness.

No, I don't size necks for measure. I just measure right out of the box.
+/-0.0001 of mean is a keeper for me.

Then, you FL size and fireform.

I don't ever FL size.
After sorting and preps, including neck turning, I just load and fire form several times with no more than bushing neck sizing. I run primer testing and full seating testing during FFing.

Do you keep the spent primer in or extract the primer and use a plug for the primer hole? Have you used rubbing alcohol? How do you ensure all the water is removed? Do you lay the brass in the sun?

I use a flash hole plug. I put only a couple drops of alcohol in water to reduce it's tension.
Blow dryer and tumbling to remove water.

 

[Ned Ludd]

I plan to shoot 300 yards and more. I have brass that I've resized but never fireformed. I plan to carefully trim them to the same length and find the most consistent volume among them. Again, I hope volume sorting works. My concern then is whether the energy used to expand these cases will affect accuracy compared to my current batch that are fireformed and neck sized.

I always throw a charge under my desired load and trickle up to my desired powder
weight.

Several items:

1) The primer pocket can be plugged simply by inserting a spent primer upside-down with a priming tool. Alternatively, you can buy [relatively] inexpensive and re-usable rubber plugs designed for this purpose. Either of these approaches allows the case to stand upright (i.e. flat bottom), which makes water volume determination much simpler.

2) The energy necessary to expand virgin brass is not inconsequential. Reproducing the same velocity from a load worked up in virgin brass using fire-formed brass typically takes anywhere from 0.1 to about 0.5 gr less powder. Fully prepped virgin and fire-formed brass are totally different animals. Does this affect "accuracy" (i.e. precision)? I'll answer this with another question, "Does velocity affect precision?", because virgin versus fire-formed brass can most definitely affect velocity.

3) From your posts, I am receiving the impression that you're using mixed brass (i.e. you mentioned sorting brass by headstamp). Is this correct? Perhaps a better question is what is the source of the brass you're prepping? If you have purchased different Lot#s of brass, even from the same manufacturer, keep the different Lot#s separate, and only work within a single Lot# when doing your sorting approaches.

If this is range brass you picked up (as I mentioned, I can't really tell from your posts), you may be able to improve the consistency of internal volume via sorting by headstamp, then determining actual water volume. However, there are no guarantees that the the case wall thickness in every region will be exactly the same among pieces of mixed brass, even if you sort them by volume first. It also means that sorting mixed cases by weight as a surrogate to volume will not be a fruitful endeavor. Other than sorting by headstamp, I would not spend the effort trying to sort mixed range brass by volume. There are too many other variables involved for that to be a useful approach.

4) Chances are pretty good that if you think up some test you wish to try, someone here has already done it. So you're doing the right thing by asking these questions. Your question regarding the weight variance between charges thrown with a machine alone, versus trickled up by hand is well-documented. Powder throwers typically have an innate level of precision (i.e. thrown charges will typically weigh XXX +/- some amount). Part of their precision depends on the powder you're using, as the size/shape of the kernels can affect the thrower's precision. Nonetheless, the precision achieved with a powder thrower alone will rarely be nearly as good as what you can achieve by hand, setting the thrown charge weight slightly low and then trickling up by hand, assuming the scale/balance used has sufficient resolution.

The bottom line is that once we have found an optimal load, we always strive to make every single loaded round exactly the same. However, there are always sources of error (sources of variance) in every aspect of the reloading process. The key is to identify the largest sources of error and deal with them first. Smaller, or non-limiting sources of error can sometimes be cumulative, but they are also generally more difficult to remedy than the largest sources of error.

My point here is that attempting to deal first with a smaller source of error when there is a [much] larger source of error present will generally show little effect. Variance in case volume can certainly be a concern for precision, but it generally takes more case volume variance than you might expect to have a noticeable effect on velocity/pressure. One way to test this is to make two sets of 5-10 cases each; one set that all reside at the lower end of the case volume range, and one set that all reside near the upper end of the range. Load the two sets with an identical charge weight, then determine average velocity with each set. That is a relatively easy experiment to determine prior to expending any great sorting effort whether the range of case volumes you're using actually cause a noticeable effect on velocity with a given charge weight. Only if the answer to that question is "yes" will sorting cases by volume have a significant effect on velocity variance.

Perhaps the hardest part of all this for reloaders is to actually identify the major sources of error in their reloading process so that those can be tackled first. The second hardest part might be deciding exactly which steps you wish to incorporate in the reloading procedure, and which are too time-consuming, or provide minimal benefit for the time required. Unfortunately, dealing with second hardest part really requires the hardest part to be addressed first (i.e. what are the major sources of error?). I have a feeling from the direction of this thread that it might benefit you to describe in a little more detail the setups you're using (both rifle and reloading setups), the reloading components you're using (i.e. source of brass, bullet type, powder, etc.). That way, responders might be able to give you a better feel for the steps you should be taking, and the steps that are too labor-intensive and are unlikely to buy much better precision. Just a suggestion.

 

[INTJ]

While Extreme Spread (ES) is a very poor indicator of potential accuracy--groups on paper are what matters; it is a good tool to see how consistent our loading processes are.

I sort cases by weight for LRBR. For both the 6 BRA and 300 SAUM IMP (formerly the 300 WSM). I usually get 200-300 pieces on new brass into two lots of around a 1 to 1.5 grain variance. The better the brass the smaller the variation.

When I do use a chronograph to check velocities, my most accurate loads usually have 5-shot ES in the high single digits to low teens--call that range 8-13 fps in ES.

That allowed me to shoot four screamer groups at 1000 yds last year during match season.

I do think internal volume is probably the best way, assuming you are able to be dead nuts consistent in how you are measuring. It's easy to be a little over or under. Weighing cases on a .001 grain accuracy scale is much more reliable.

With the batch of ADG I just sorted, 297 cases showed a variation of 2.1 grains. There was one outlier, and two cases were sacrificed for other duties before weighing. I now have two lots that have a weight variance of about a grain. I have no concerns about these cases allowing me to shoot screamer groups this year.

Thinking about it, it's the case volume at the time of firing--when the case has expanded to fit the chamber right before the bullet is released--that's the critical volume. Dimensional consistency would seem to have the most effect on that, as well as consistency in bullet intrusion in the case.

 

[Bronsin]

I used to sort by weighing cases, and it just seemed to make more sense to actually measure case capacity and see what it really was. I used fired cases with the primer still in, and then filled them will ball powder. The cases were for a .223. What i found was that for every change in capacity of .1gr., the case was .3grs heavier. On a case as small as the .223, it seemed ridiculous to sort cases by .5gr when it didn't even change the internal space by as much as .2grs of powder. Now I just weigh them and throw out the oddballs. then sort them by wall thickness.