Could someone explain to me whats the proper way to sort brass? What weight differance would make it unexceptable. I used a digetal scale to weigh a few and came up with a total differance of 2.2 grains, heaviest to lightest. Is this too much?
I (when I do this sort of thing, no pun intended), build a Bell curve and take the majority fron the center of the distribution, the remainder are tossed away or used for junk loads. I place a strip of masking tape along the edge of the bench and label it by weights, I weigh the brass and put them in columns according to weight, I use .2 gr increments. When I'm finished I have a nice Bell curve (if I have a standard set of brass (one lot). If I've mixed the brass (multiple lots) I may get overlapping curves (twin or multiple peaks), sort of a crap shoot them.
Shoot the brass at 300 to 400 yards and sort it by the ones that go into the group (you may want to number your brass with a permanent marker so you cam keep track of your brass) separate the flyers and load them one more time to see if it is the brass that caused the flyers.
If you think something is not possible move out of the way so the ones that are doing it can
When doing load development I go for consistancy. I use a technique similar to the one Dave King poster, sorting them all out. Once I have them all sorted, I will take groups of 3 or 5 (depending on how many I am shooting to deem "good") that have the same weight (or within .1) and load them up with a particuar recipe. I also will inspect everything I am able to check on the brass to make sure it should all weigh the same.
Interestingly I used to get about the same accuracy before I had a digital scale and used this method.
2.2 grains sounds right to me. I just set aside all the ones that don't fit in for another loading, or for site in and plinking rounds.
This has been a topic of much debate and there are other posts on this board. For me, what matters is case volume and brass quality.
I will have to assume that brass from the same company and same lot are as close to identical as can be manufactured. You could of course anneal necks just to make sure.
On the volume issue, I have found that cases vary very little in internal volume dispite varying quite a bit in weight. My thought is that the extractor groove is one of the largest sources of weight error but has no affect on the accuracy of the brass. So you could have brass that weighs the same but have different internal volume.
I sort my fireformed brass after neck/FL sizing by trimming all to the same length. Then I use a very fine powder and dump from case to case, tapping to make sure that it all goes in. If any case is significantly bigger or smaller, I cull that (very few get culled). The rest are loaded with an accurate load and test fired. Any shot that is a flyer gets retested. If it shoots outside the group again, it gets tossed.
This way I have been able to get match accuracy from all types of brass, including military stuff. They don't weigh the same but shoot the same. What matters more to you?
Ditto what Jerry said. I've been wieghing mine with water out of an eye drop bottle tho. Internal capacity has been so close it's scarry, even when the case weights vary considerably. Extractor groove is the only place the variance in case weight could be coming from too. Takes about an hour or so to verify the internal capacity on 100 rounds, keeps you from wondering or culling stuff that never was even different to begin with. I've done 460 cases this way so far and haven't threw a single piece out, as they were all with in .2gr of each other.
The first ones I ever did were from three different lots of 300 Ultra brass too. So needless to say, I wasn't all that surprised to find the other 300 Ultra, 338 Lapua, 243win and 308win brass to be within this range too. It was all Lapua brass except the Ultra stuff, which was Remington.
I had some old Winchester 308 brass I pitched that I wish I could have checked, it had case weight variances of somewhere upward of 15gr if I remember right. All this stuff I checked here was under 5gr, so the Winchester stuff might have showed it needed batching. I had them in .5gr batches already, so suffice to say, I had quite a few batches of them buggers, and what a pain in the ass that was too. The Winchester stuff came from about 5-6 different lots of bulk brass I got locally at different times, and it still was different than the bags of brass I got later on too. Most of it all fell in the high range and the low range with not many right near the middle tho.
I still don't know what range of capacity would be acceptable and what wouldn't but, so far everything I've checked has been in line with all, but the most anal BR shooters see as acceptable, so I'm happy so far. Not having different weight batches to deal with is refreshing to say the least, wish I could say that abot bullets... Now the Juenke I.C.C. adds more batching to contend with. Haven't even got to batching by bearing length yet, and by the way, how the hell do you suppose I'll organize 'em all at that point!! Suppose I'll have to drop down and start shooting 3 shot groups again! [img]images/icons/grin.gif[/img] [img]images/icons/rolleyes.gif[/img] Buying bullets in 500 round lots would sure be a good start.
I have also read many BR shooters now measuring ogive and bearing surface lengths. Does this take into account the jacket distortions that occur during firing, filling the throat and engaging in the rifling? What about jacket and core hardness? Does moly reduce jacket stretching?
I guess we will be using MRI and xray machines next.
The irony is that all this fiddling is good for maybe another 10 to 15% reduction in group size. So about 1/16" with most 1/2 MOA rifles. The misjudging of a wind by 2mph will move your bullet how far at 300yds, at 1000yds?
Like many amature golfers, shooters are looking for an edge that may only exist in their brains from a widget marketed to solve a nonsensical problem.
The bottom line is that burning powder in a consistent rifle to improve your ability to judge conditions and your shooting skill will serve you more then fiddling with 0.001" of anything. Besides, doesn't fouling in the neck screw all that up anyways...