Disappointed - Lapua brass sorting

[gravelyctry]

Well, based on some feedback I'd gotten earlier, I purchased 300 pieces of Lapua brass in 308 Win to start making some long range loads.
I trimmed, chamfered, deburred, expanded, neck turned, etc., and then sorted the brass. I was anticipating good things, but ended up very disappointed. I had two distinct "groups" of brass weights, as you can see from the attached snapshot.
Has anyone else experienced anything like this? Is there anything I can do about it?
I should note, that all three boxes of brass I received were from the same lot (P00446002), and all other numbers were identical between the boxes of brass.

 

[jghoghunter]

Sorry about your outcome. I just sorted a 100 308 lapua and had a +/- .5 gr. over the whole 100.

 

[JERRYHM]

Do you really think that weight sorting makes any difference?

Take the lightest and the heaviest, very carefully load and shoot them at 1000 yards.

Case weight doesn't = case volume.

The new Lapua 308 SMALL primer brass will be better, so sell your brass asap.

 

[gravelyctry]

Jerry, to be perfectly honest, I don't know if brass weight sorting makes a difference. I'm following the advice given by others as I prep my brass in an attempt to remove any variables from my long range loads. I don't believe weight sorting will hurt me, so why not do it?

Lapua brass, according to their advertising, is supposed to be the most accurate and consistent brass available. I'm posting this as I was very surprised/disappointed that the case weights weren't more uniform, and was curious whether this type of spread was typical or not.

 

[audredger]

Did you copy my sorting data?? Looks like what I got from my 200pcs of Norma 300WSM. 1 super light and 3 way heavy... setup cases.

 

[Laurie]

gravelyctry,

you get this. Even though Lapua is generally regarded as the best around, there are good batches and not so good batches of .308W brass from this company.

Based on your weight distribution histogram, simply batch around the two peaks - ie a 'light' group' and a 'heavy' group. It may or may not improve the resulting ammunition performance at long range, but certainly won't do any harm.

What may have a bigger effect is neck thickness variations that have an impact on neck tension, and that is worth having a look at, and batching on the results if appropriate.

Laurie,
York, England

 

[CFS]

I have never found weight sorting to have any benefits.

Pop

 

[dantiff2]

WOW I look at your chart the other way around. I think an extreme spread of 2.9 grains over 300 pieces of brass is excellent! You'll get more than that over 50 pieces of the competitors brass.

Dan

 

[762willdo]

"New lapua small primer .308 brass" WHAT WHEN WHERE i gotta get some!!!!!

 

[NateHaler]

Well, based on some feedback I'd gotten earlier, I purchased 300 pieces of Lapua brass in 308 Win to start making some long range loads.
I trimmed, chamfered, deburred, expanded, neck turned, etc., and then sorted the brass. I was anticipating good things, but ended up very disappointed. I had two distinct "groups" of brass weights

Lesson learned friend. First, you sort by weight. Then, in a case (no pun intended) like yours, you sell one batch of cases -- because they are still in BRAND NEW UNALTERED condition. Meaning, somebody will surely buy them, and you haven't wasted HOURS doing prep on them. Prep for which many buyers won't want to pay a premium.



Lastly, listen to what Jerry says. Do what he does. Or at least try. ;D

 

[dreever]

Sometimes i think we can get waaaayyyyyy to anal over some of this stuff. Pick what you consider the best and worst and shoot groups with them and i bet you won't be able to tell the difference.
I used to uniform flash holes and primer pockets, weigh sort all my brass into batches buying 500- 1000 pieces at a time. Hell, i was so anal i even weighed primers and wore gloves when handling them.
After years of successful Jack Daniels therapy i've since given up on a lot of those things.
Here's some facts that I proved by accident to myself: The best short range benchrest score i ever shot which was a 250-24X I shot with practice brass with a bunch of loadings on it using pulled bullets, and pre-weighed powder charges! The best 600 yard group I ever shot was again not with my "Perfect" match brass, but with old practice brass that I was forced to use because I ran out of loaded match rounds.
The best long range group that I ever shot was with new right out of the box Lapua brass that i didn't touch the primer pockets or flash holes, never weigh sorted, and no neck turned.

I'm more and more begining to think that a lot of the "VooDoo" we do dosen't mean Jack Shit (Pardon my french) if you know what I mean.

Danny

 

[Laurie]

Danny,

successful Jack Daniels therapy

Yes, I discovered this version of the well known treatment too this Christmas as an alternative to our usual 'Scotch' variety - the local supermaket had a two bottles at large discount promotion on! JD is normally very expensive over here.

It does help put things into perpective at times.

Laurie,
York, England

 

[dreever]

Laurie,

Ah, I've been known to try a taste of "The Dimple pinch" or "Glenmorangie" now and then.
My all time favorite though and rather expensive, would be "Bookers Bourbon" which Santa sometimes brings me when i've been good. Alas this year I must have been bad because no Bookers under the tree!

Danny

 

[Steve Blair]

This post of mine shows almost the same experience. Same number of rounds, different lot, similar result.

I sort to .25%, so these 300 produced 50 in .42, 50 in .36, 100 in .26, and 90 in .42. They will be shot as separate groups.

Years ago, I did try the experiment that JERRYHM suggests, but at 600 yards. I had three times the vertical dispersion as from sorted brass. The light brass shot low, the heavy brass shot high. That experiment was run with FA64 (Frankford Arsenal for the experience challenged) and the 5 low and 5 high pieces were separated by slightly over 6 grains. My 300 Lapua .308 had an ES of 2.4.

I have loaded 50 from the second group and intend to measure the case volumes after firing. I have also loaded the lightest and heaviest to shoot as foulers and will measure them, too. I will attempt to correlate volume against weight.

 

[Laurie]

"Bookers Bourbon"

Danny,
Haven't come across that one over here. I can tell though you are a man of refinement and taste as soon as you mention Dimple and Genmorangie.

Go into a good booze shop here, not to mention those that specialise in Scotch, you'll find we have so many varieties of the 'water of life' that you'd be long dead from chirrosis of the liver before you sampled a bottle of each.

Do you have a breed of killjoy doctors in the USA who want all alcohol banned, and if not that, have so much tax put on it that only the rich could imbibe (plus the feckless poor who drink even if they have to steal to do so)? I regard such with the same warmth and feelings of brotherhood as I do for the large anti-gun owning and anti blood sports factions we have in the UK.

Good shooting in 2010, and may you enjoy the odd wee dram too,

Laurie

PS I should emhasise I cannot afford Dimple or Glenmorangie being a poor semi-retired individual with a 6PPC bench gun and large family of other target rifles to support, not to mention hordes of Lapua cases to (spuriously) attempt to get back onto topic!

 

[boogershooter]

I gotta agree with Dreever on this one! I have drank some ugly girls pretty,and some fat girls skinny, with the help of Mr. Bacardi. Figure I can drink my brass to a "close enough" weight also ;D Cheers !

 

[Clark]

When you see a double hump Gaussian distribution in resistors, someone has already sorted, and taken the good stuff.

 

[gravelyctry]

Clark - that was actually my first thought, and I started wondering if Lapua offered something like "select" brass that had already been sorted based on weight. But I didn't see anything like that available, and the boxes were still "sealed" with their factory sticker.

 

[Rust]

Used to have a lot of time on my hands. I tried to quantifiy what effect differences in case weight made.

Using a chrono, and the same loading, a 1.0 gr change in case weight changed velocity equivalent to a 0.1 gr change in powder charge. Meant I had to use cases from the extreme ends of weight from the same batch to really determine much difference. The faster the powder the more pronounced the effect. In .308.

In .223 it was much more pronounced. A 1.0 gr change in case weight was about equivalent to a 0.25 gr to 0.3 gr change in powder charge weight. Touchier regarding powder (powder burn rate) too.

As always YMMV.

 

[RDavies]

Looking at the graph, I would say batch it into 4 lots. You have to split the brass up any way, unless they sell 300 round ammo boxes now?
How about use the same load in all cases, but if you are shooting on a cool morning, use the heavy cases, which will keep the velocity up in the node, which might have dropped down due to low temps. If it is a hot day, use the lighter cases to knock some of the excess pressure,velocity off.
I dont personaly weigh cases due to lack of time, lack of good scales and not currently competing in 1000yd BR, but a large amount of high scoring BR shooters do it.