Brass sorting?s

[zr600]

Ok once all your brass prep is done and you sort your brass by weight how much of a difference do you allow for like match quality accuracy?

[Rob01]

Use quality brass and no need to weigh them.

[243LPR]

Usually sort to within 1 grain of each other.

[darkker]

I don't sort my brass, except buy caliber.

Here's the problem with your view, my view, Rob's view.
What you are trying to get, consistent volume, is admirable; but your method flawed.
Volume is volume and weight is weight, short of a possible corrosion they never meet. Unless you know the specific alloy used, and how tight the tollerances for ingredients. And you know how many machines in the lot of brass confess from, and what their SD is for diamensional variation.... If you did know those answers, you would also know that each lot is different, so the single answer you are asking about; wouldn't be a single answer. "Match" brass would be subject to the same production tolerances, although you would ASSume them to be less, but don't know; so possibly would need sorted as well.

Rob says buy quality brass and don't worry about it. He is a very good trigger man, so must be on to something. I say don't worry about it at all. I Pressure Test stuff all the time, so I must be on to something.

See the problem yet? If you want to know how much internal volume difference there is, measure it.

From the 50+ years worth of 308 headstamps I use and have Pressure Trace data on, it doesn't matter. I Pressure tested some of the "Oh no! That year LC Match brass is scary different". Again, couldn't find any significant pressure change. Is it possible it matters? Heavens yes! But Everytime I've tested The new magic bullets, or the brand difference, or the "known" brass; I just don't find what is claimed.

[bigedp51]

Preparing Cases for Long-Range Accuracy (one grain limit)
http://www.accurateshooter.com/technical-articles/reloading/complete-precision-case-prep/

Lake City M118 Long Range ammunition is made from weight sorted M80 brass and falls into a two grain weight variation. I can't find the Lake City posting but it stated that 61.24% of M80 brass fell into the two grain weight limit and the M118 LR cases were selected from these cases.

I bought 300 once fired 7.62 M80 cases and sorted them by head stamp and weight. And I'm not going to fill 300 cases with water when the military uses weight sorted M80 cases for their M118 LR sniper ammunition.

I do the same for my once fired Lake City 5.56 brass and as you can see below Lake City brass is high quality brass. And far better than Remington and Winchester brass and a fraction of the cost of Lapua brass.

http://i.imgur.com/PExmCCk.jpg

http://i.imgur.com/LjAQ7L9.jpg

How Hard is Your Brass? 5.56 and .223 Rem Base Hardness Tests (and Lake City brass is made Ford Truck Tough)
http://bulletin.accurateshooter.com/2014/05/how-hard-is-your-brass-5-56-and-223-rem-base-hardness-tests/

[bigedp51]

Found the link, its a good thing I'm retired with nothing to do and all day to do it.

Case Weight Variation Reduction and Subsequent Ballistic Dispersion Improvements in M118LR

http://www.dtic.mil/ndia/2010/armament/WednesdayCumberlandDionneDillon.pdf

And this 2 grain weight variation in case weight was good enough for the Navy S.E.A.L. sniper Chris Kyle's pinpoint accuracy.

[darkker]

Let's clarify a few things about that. They didn't say that 118 is sorted from M80, they said they WERE essentially the same with a slightly stricter primer pocket and weight requirement. They then went on to say that NOW M80 & 118 are built by the same process. So they weren't just sorted. The % within a range is just a standard Bell curve, that isn't an absolute either.
The funny thing about that info is the source.

Picatinny and another arsenal long ago did a weight to commune study on the various 5.56 makers, going down to reach individual production line.
So to release some fluff about being a relationship between volume and weight... It's no wonder the G brought in General Dynamics prior to 2010, to show ATK how to pump out enough ammo for the sand wars. Also not surprising ATK lost the contract to Radford arsenal.

[bigedp51]

Let's clarify a few things about that..................

M118 LR cases are weight sorted and have a two grain allowable weight variation.

"AND" weight sorting is good enough for Long Range M118 sniper ammunition.

"AND" the OP asked about weight sorting..............


Ok once all your brass prep is done and you sort your brass by weight how much of a difference do you allow for like match quality accuracy?

[geargrinder]

Use fine sand or salt for measuring case volume. Top off to the mouth of the case and weigh.

So much easier than working with water and you can get a measured volume comparison of you cases instead of you assumed weight/volume relationship.

I only measure volume after fire forming and sizing just to make sure all of the external dimensions are consistent.

[Robinhood]

I see no value in volume unless each case is held to the same dimensions externally. I see no harm in weight sorting. I believe neck tension consistency and using same brand/lot of brass to be of great value.

[m12lrs]

One guy's method for long range brass prep. Personally though i think his plan is solid i would never go to this much trouble.

And at each step of.reloading there is another detailed process. Bullet sorting, powder weighing it goes on and on.


My question is what are the important ones and if.you just do parts of it then are you really just wasting your time.

http://www.accurateshooter.com/technical-articles/reloading/complete-precision-case-prep/

Personally i buy lapua brass and call it good.

[Robinhood]

Most people don't know the authors credentials.

[Rob01]

I do and have shot matches with the author.

[Robinhood]

I am not surprised one bit.

[m12lrs]

Most people don't know the authors credentials.

Well there are as many opinions out there as there are long range shooters. They all do some things differently. It is all about what works for you but if you don't try different things you will never learn.

This guy has a pretty good list of things to try. His credentials are pretty good. If you want to know more about him there is ways google. He writes for several magazines


About the Author
Jacob Gottfredson has written for several magazines for the past 20 years, including GUNS, Guns & Ammo, Safari, Tactical Shooter, The Accurate Rifle, SWAT, Tactical Response, and Precision Shooting magazines. He specializes in long-range, precision rifle, technical reloading, and optics. He has contributed chapters to four books. An ex-Special Forces soldier, Jacob has competed in Sniper and Tactical competitions for several years. For the past 25 years, he has competed in 100/200/300 and 1000-yard benchrest competition. He has hunted since the age of eight, taking him to Canada, Alaska, and Africa. He grew up in the Rocky Mountains hunting deer and elk as well varmints of all sorts. Jacob has degrees in math and engineering, and he holds a masters degree in structural engineering. Jacob presently owns and operates an engineering firm, and is a Professional Engineer in Texas and Utah.

[Robinhood]

My apologies. I wasn't challenging your google foo. I was supporting for your choice of articles to post.

[Rob01]

I got to try and find the picture we took of Jacob back at Rifles Only in the mid 2000s shooting a stage with a cigarette hanging out of his mouth. He was always fun to hang and shoot with.

[darkker]

1) M118 LR cases are weight sorted and have a two grain allowable weight variation.

2) "AND" weight sorting is good enough for Long Range M118 sniper ammunition.

3) "AND" the OP asked about weight sorting..............

1) Maybe they are. The link you posted doesn't say that though, was simply pointing that out.
2) Never said it wasn't. Not weight sorting was good enough for any similar use prior to that. Further pointing out there isn't a single answer to the OP's question, short of "it depends on a few things".
3) I agree, which is why it depends. All links posted including yours has some very good info, but none of them give a universal concrete answer.

[m12lrs]

Well the answer for the OP is only the target can tell the tale

Try both weigh sorted.and unsorted. Is there a difference for you.

Lots of.other things to do in the search for accuracy. Only you can tell which ones make a difference for you.

[s3silver]

Keep them all the same headstamp and you should be good to go. As mentioned in other posts weight does not translate into internal case volume. I don't weight sort or neck turn, but I would probably neck turn before weight sorting so I can at least attempt to achieve consistent neck tension.