Does sorting large rifle cases by weight improve accuarcy ?

Just bought 100 Norma 270 wsm cases. Every thing I read said the varation in Norma cases was very slim. The varation in weight from my last batch of rem. cases was a little more than I thought they should be so I decided to try the Norma.

I weighed the norma cases just to see how uniform they were. Here are the weights.

25 rds. 240-241 grs.

46 rds. 241.1-242.1 grs.

20 rds. 242.2-243.2 grs.

one rd. each at 239.2, 243.5, 243.9, 244.9.

two rds. each at 244.5

three rds. each at 243.7

My question is do you guys think this variation is acceptable? How about for high priced Norma?

Should I throw out the heaviest and lightest piece and reconfigure these into three batches, or throw them all back in the same bag load um and shoot um ?

skunk

I shoot long range Benchrest and sort my brass by weight. I generally figger that a plus or minus 1% variation is pretty good. It looks as though you are very close to that range. If it makes you feel better, use the very lightest and very heaviest for adjusting dies, making dummies, sighting in, or whatever.

For a hunting rifle I think you are OK. If you want to do more sorting, load up and then sort the loaded rounds by weight from lightest to heaviest. Put them in boxes that way and use them in order of weight.

Or just forget it and shoot. But never underestimate the mental aspect of shooting. If you THINK your ammo is better for some particular reason, say good brass, then you will PROBABLY shoot better.

Ray

Yes, sorting large rifle cases by weight improves accuracy.

Yes, I think the variation is acceptable based on the number of cases per weight group. I think Norma, Lapua, RWS, etc are worth the price. Quality and consistency of brass is the key element to accuracy.

Throw out the heaviest and lightest and reconfigure into three batches. You will get more cases in the future to match the weight of your heavy and light cases. This is a probability game and Norma is one of the best at consistency.

Being a short range BR shooter I have to agree with Cheechako. Since it is a hunting rifle I think the effort is not worth the gain. But if it makes you feel better do as Cheechako says

quote:

Originally posted by MSwickard:
Being a short range BR shooter I have to agree with Cheechako. Since it is a hunting rifle I think the effort is not worth the gain. But if it makes you feel better do as Cheechako says

I have an email here from nosler that a person can by in large quanities(multipules of 50) direct from them wieght sorted from within the same lot +/- .5 grains.

A little perspective for what it is worth.
Brass is about 8 times the density of powder or water. It takes 8 grains variation in the case weight theoretically to be equivalent to the volume change made by one grain of powder.

quote:

Originally posted by ireload2:
A little perspective for what it is worth.
Brass is about 8 times the density of powder or water. It takes 8 grains variation in the case weight theoretically to be equivalent to the volume change made by one grain of powder.

Now that is some relative information that puts things in perspective. Good info, ireload2.

Ed is right on... Nosler weight sorted brass is the best bang for the buck if they make what you need. Norma is good and strong brass but for the money...go Nosler. I used to weight sort brass but the hassle is not worth the slight gains in accuracy(if any) unless your trying to get the last bit possible. Just not necessary for hunting rifles.

Woody

quote:

Originally posted by ireload2:
A little perspective for what it is worth.
Brass is about 8 times the density of powder or water. It takes 8 grains variation in the case weight theoretically to be equivalent to the volume change made by one grain of powder.

Maybe that's why weighing cases never did me any good.

We weigh the cases to get the internal volume. It will be more accurate to measure the actual volume (by using water) to sort cases. I don't bother because for hunting accuracy the most important factor is the hunter.

Skunk, are you weighing these cases before or after you uniforme primer pockets, deburr flash holes and trim to length?

quote:

Originally posted by Cheechako:
... But never underestimate the mental aspect of shooting. If you THINK your ammo is better for some particular reason, say good brass, then you will PROBABLY shoot better. ...

Hey Skunk, Absolutely agree with Ray's above quote.

It doesn't take all that long to do, and you only have to do it one time. Of course, do all the Case Prep first, as Eddie mentioned.

I keep a running Talley on a sheet of paper with each individual Weight. And I put that Weight on a piece of Scotch Magic Transparent Tape which goes onto the actual Case. You want to use this specific Tape because it will not leave a glue residue when you finally remove it(voice of experience).

Then take the Tally Sheet and "re-list" them from the Lightest to the Heaviest and you generally get the old inverted U-shaped curve, with a few strange ones at each end.

Now you can go through the Lot and break them into any size amounts you desire, with many the exact same weight.

Shoot them and mark one of it throws a Flier. If it throws a Flier on the Second Firing, use it for something besides your Hunting Loads.

Confidence in the Final Load makes it well worth the small effort on a Rainy day. Best of luck to you.

You GOTTA be kiddin me .I did trim to length, but haven't done anything to the flashholes.

I thought the reason for paying double for norma was because they were so uniform, and the flash holes were drilled with no burs!!!

Assuming your .270 WSM is a hunting rifle with a standard SAAMI chamber, weighing cases (like neck turning) is probably not worth the effort. Spend the time fine tuning by playing with seating depth as this will have a more profound impact on accuracy.

Yes, Skunk. It would amaze you what some of these folks do to their brass when they could be out shooting. I have weight sorted brass and found it to be an exercise in futility.

Some of you may think that brass selection, and all the other things that precision shooters do, is a waste of time. I'm here to tell you that there are times when you're right. But todays rifles, even those you buy at the local Walmart, are surprisingly accurate right out of the box and even more so with just a little bit of extra work and attention to detail. Sure, if you're shooting grandaddy's 30-30 at tin cans it probably doesn't make a bit of difference. But once you get in the habit of doing all those little things it's surprising how it becomes second nature and you find yourself prepping brass for every rifle and handgun that you shoot.

In competition there's an old saying that goes something like this. "Don't do anything to make your ammunition better. It means more trophies for me." I'd say something similar to you guys. Don't do anything special to your ammo. When shooting at that deer or antelope or prairie dog, and you occasionally hit one, it proves that what you're doing, or not doing, must work.

JMHO

Ray

Like with most things that require precision or athletics or both, the last 5% makes a huge difference if you're trying to get the absolute most out of whatever it is you're doing. Trouble is, that 5% is where it's hardest to make measurable improvements. Everyone has to decide whether or not it's worth it for them. For my sanity, I always have my favorite plinker rounds that I can just load 'n go...

There is shop time and range time. Where do you want to spend your time. Or to put it another way, do you shoot to reload or reload to shoot.
For the owner of a factory to go into all the anal and often superfluous steps that bench shooters do is kinda like putting a english saddle on a dray horse. It still ain't gonna make him a race horse. When it comes to weighing cases and turning necks and such, I think everybody ought to do it at least once. And find out for themselves if its worth it or not to them.

I have to agree with some of the opinions here, not with others. I weigh my varmint cases and for long range shooting (1,000yds). This has proven to be helpful.
For hunting loads, usually, this is an unnecessary step. Note the word usually. Twice I've come across case lots that had over a 10 grain difference between high and low! This definitely caused some flyers...that's why I weighed them. One was a .25-06 that normally shot under an inch. After weighing, back to normal.

Skunk, I was not kidding. Since you did not say what kind of shooting you were prepping brass for, I thought I would ask. The reason for the question is if you plan on uniforming primer pockets, deburring flash holes and trimming to length, do so before you weight sort the brass.

After extensive testing, my experience has been that the decrease in group size is statistically insignificant in game rifles.

It may be different in varmint guns, but I don't shoot those.

You're only talking about a 2% difference in the weights given anyway.

Just my ignorant farm-boy opinion but I'd like to try and sum it up in one sentence.

Prepping brass and all the other attention to details is the difference between a RELOADER and a HANDLOADER.

Ray

Skunk,

This is a late reply to your question, but I believe my reply will be helpful. Weight-sorting is a simple means of testing the uniformity of the production process.

Take the weights of your brass and enter them into a computer spread sheet. Get the average weight and the standard deviation. Multiply the std. dev. by 3, and set confidence limits by adding and subtracting the three std.dev.'s to and from the average weight. Any pieces of brass whose weights lie outside of these limits should be discarded. What we have determined is that these pieces had some variant introduced to their production that is not normal to the process.

We have done nothing that says that the performance of these pieces of brass would not perform the same as the others. We have only determined that the production process was different.

To sort brass by performance, take the fireformed (once-fired) cases and measure their individual water capacities. This statistic directly correlates with chamber pressure. Grouping cases this way reduces the extreme spreads of pressure and velocity.