I have been noticing that my brass is having a 1to2.5 grain weight difference.Some of the cases are noticeably Fuller than others.Will this affect accuracy or over pressure problems.I am using imi , lake City and wolf brass.Thanks in advance for any advice

It depends how sensitive your load is.

If your load can tolerate +/-0.3gr you probably won't see much of an issue.

If it's only tolerant to +/-0.1gr then you may have an issue and should redevelop anyway.

Ideally you should measures case capacity of fired cases rather than going by weight but you mentioned some look fuller than others so....

I don't recall the exact results but I tested a bunch of LC .308 brass by weighing cases, separating the heaviest and the lightest, then measuring the H2O capacity. I found very little correlation between weight and capacity. Some of the heaviest had the same capacity as some of the lightest.

I now use Lapua brass because I got sick of wasting time prepping and sorting cheap brass only to lose it to case head separation at 4x firing because of poor wall thickness concentricity.

I know you like 6.5 Grendel's .I just reciently purchased awolf upper 16 in wanting to shoot steel ammo through it best I could at100yds was a 5in group.i contacted wolf and they said that was normal so I bought some Hornady 123 grain and guess what I got1 in groups so I am starting to reload my own.i purchased some 90grain Speer bullet and going to try them this weekend.what type of lite weight bullets have you had success with?

I used the 90gr Speer TNT for a plinker load(don't want to use bimetal jackets through this bbl). I didn't develop it I just picked a charge and it worked decent enough for my needs as a plinker.

32gr of W748 at 2.190" OAL, it was 2760fps out of my 24" bbl

This is avg for it.
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I use mostly Nosler 140 CC now for plinkers because they are cheaper, work decent to 750yds or so and they are boat tails, I hate loading flat base bullets.

I don't use anything under 140gr now.

To the OP.

A reloader should segregate the brass by headstamp.

And, mixing brass is counter productive.  Because what is safe in one brand might not be in another.

You are wasting your resources if you are not doing the above.

A load worked up in in Win brass is probably not close to safe in say Fed brass or LC brass.

There is no cross over or substitution with brass nor primers in rifle ammo.

Be consistent and you will have set the foundation for accurate, reliable and safe ammo.

I use Winchester commercial brass and Lake City surplus. I keep them separated and don't worry about case to case variations.

My only warning is to check foreign made brass before loading it. I purchased loaded surplus Portugese ball in the 80's (dated 79) that was HOT and after shooting the entire case I decided to reload the brass.

The first thing I noticed was my standard charge nearly filled the case to the top. I weighed a half-dozen empty unprimed cases and they averaged 104 grains!

10% heavier than my heaviest USA brass. The headstamp was marked FMN-79.

I lowered my powder charges 1.0 grain for that brass. I used it for blasting ammo only and left the brass at the range so it never entered my reloading stream again.

If you use 5.56 brass like Lake City, you can get a rough idea of case capacity by weight. I have water measure tools. They dont work well for SORTING. It is far too slow and cumbersome. For sorting you want once fired, spotlessly cleaned with a wet tumble, then lubed. full length resized, then recleaned to remove all lube with a second tumble, fully trimmed brass. Then sort by weight.

The commercial brass vs match Nosler or Lapua brass is not trimmed to length and variations can create weight differences in length alone. Cull the outliers high and low and you have sorted your brass by WEIGHT. You will also want to sort by neck concentricity and sort again to cull non neck concentric brass and brass with uneven neck thickness. Again just cull outliers.

Finally, dont mix your brass by firings. As you reload the 2nd, 3rd, 4th, etc. time, not only does neck tension change due to working the necks, but the body changes shape by thinning near the case head and primer pockets will have uneven tension. If you try to keep good data mixing brass of different furings will drive you nuts.

I have found zero statistical differences in uniforming primer pockets or flash holes. If anything, I got a micro reduction in acccuracy and worse SD but I think it is just noise.

FYI, I only use Lake City, Norma, or Lapua brass. Norma is best right out of the package for uniformity, weight, and trim length. Lake City the worst. Lapua brass is so thick and of different material properties it lasts the longest but changes your load requirements. With Lake City brass I have found some lots are more or less concentric and that is a bigger deal than weight sorting. You cant make a neck with over 3 thousands non concentricity accurate. I have not found any Lapua or Nosler brass with uneven neck thickness and almost all of it is 1 thou or under on neck concentricity.

This isn't really true, for headstamp sorted brass.

The study that people usually cite, the ages old one from accurateshooter, found no correlation between case weight and case capacity in mixed-headstamp brass.

I never understood why they did it that way, since it's ridiculous to think that anyone who'd weight sort brass wouldn't be working with same-headstamp brass, if not same lot same-headstamp brass. In short, that study and their data are garbage.

In any case, I've personally measured H2O case capacity and case weights for a number of calibers and manufacturers using same-headstamp brass, and the two are highly correlated. The only data I have handy is for some factory Wolf primed brass (Taiwan manufactured, not crappy combloc stuff) that I tested a while ago. For that brass, the correlation coefficient (R) was .74, which is compelling.



Whether any of this makes a bit of difference on target, especially at .223 Remington distances, is another discussion. But case weight is an excellent surrogate for case capacity - if you're dealing with headstamp sorted brass.

Again, do with the data what you will; I'm simply pointing out that the oft-parroted conventional wisdom that weight does not correlate with capacity is provably, factually, wrong.

This is a precision reloading forum. Of course people are anal. You've got neck turners and people weighing charges to the kernel on $1000 lab scales and flash hole deburrers.

As a further exercise, play around with case capacity in Quickload. The data from the brass lot I posted above showed that the difference in .223 case capacity between a 96 gr case and a 100 gr case was a full grain of H20. That kind of difference in case capacity meaningfully affects pressure and velocity. Is it worth the time to cull the handful of 96 and 100 gr cases from that lot of brass and only shoot the 97-98 ones? Maybe. People do much sillier and time consuming things than weighing brass to cut their velocity variation and vertical dispersion at distance.

I'm not trying to talk you into doing it. Indeed, I specifically noted that the effect may not be worth the effort:

And if you'll recall, my original post was in response to this statement:

This is wrong. I posted actual data demonstrating that this statement is false - at least for the lot of brass I tested. (And, incidentally every other batch of same-lot brass I've tested.)

I disregard the different findings because, as I mentioned above, the accurateshooter study that birthed this myth used mixed headstamp brass. GIGO.

If you have other data, post it. Or not. Happy shooting.

Comparing Wolf, some of the cheapest brass available, to anything isn't really a viable test. Even using them as the standard it only varied 1 grain on extreme H2O despite weighing almost 4 grains different when just weighing brass.

Using the same headstamp and discovering the average weight of unprimed cases gives the user a baseline from which to proceed. If my lot of Winchester .223 brass averages 93.0 grains +/- 1.0 grains I know for a fact my foreign made brass that averages over 100 grains empty and unprimed will need a different powder charge (lower).

We are shooting (most of us) AR-15 semi-auto rifles, not 1000 yard benchrest rigs. Weighing cases gives the reloader a window of data to insure they don't get surprised. Resized and trimmed brass from the same lot number will shoot acceptable well as is. Even culling the extremes (the heaviest and lightest extremes .5 grain away from the average weight) is not likely to show up on target until you get past 600 yards. Maybe not even then.

People can waste time and effort chasing after these ghosts, I know I did 30 years ago when I first got started, but you'll find excellent results for half the work by just buying quality bullets.

People make things harder than they need to be with the honest belief that perfect ammo will create a perfect score. If you want better results on target practice shooting more.

this 100 times.   I only do mixed head stamp in my plinkers which are probably 2-3 gr under max to account for differences in case volume.

sort the cases, do your loads and pick which combination shoots better out of your rifle.

The answers to sorting by head stamp, sorting by weight, or sorting by water capacity is worth it is pretty much always "it depends" because the details matter.

For example, I bought a large batch of new 7.62x51mm NATO brass to replace the 5000 or so LC match cases that I acquired and then wore out in the years since I shot competitively.  However, I discovered that their water capacity was nearly identical to my Federal Gold Medal Match brass, with an average of 53.4 grains compared to 53.6 grains (0.37% percent difference).  This isn't much of a surprise when you consider that the LC 15 brass was actually made by Federal, and that Federal GGM is also used for loading military M118LR.  In short, the head stamps are different, but the brass comes off the same machines.

Those LC 15 cases are significantly lighter than the normal mean for my various lots of LC match cases from the late 1960's through the early 1980s and the water capacity is less at an average of 52.2 grains (2.5% difference).   In other words, an LC match head stamp alone isn't sufficient to indicate the brass is the same, unless the era or even specific year is also considered.

I also have a batch of older Winchester brass with an average water capacity of 56.4 grains -  5.4% different than the LC 15 brass and 8% different than the older LC match brass.  The kicker is that Winchester has started sourcing their brass from different manufacturers, so just because the head stamp is the same, doesn't mean the cases are the same.

----

To be fair, the variation in 7.62x51 and .308 Win head stamps is greater than most.  And US made .223 Rem and US made 5.56x45mm NATO brass is comparatively homogenous with much less difference in water capacity between head stamps - which is why firms like Black Hills Ammunition's blue box remanufactured ammo used mixed head stamp brass and still produces MOA or better accuracy.   However, when you start mixing US made brass with IMI brass and in particular Russian made brass, you're getting back into serious case sorting territory.

Factory or store bought ammo is great for breaking in a rifle but if you're attempting to develop precision ammunition then it's a waste of time to reload with that brass for anything other than plinking and maybe hunting. You can end up chasing your tail.

Start with new brass from a reputable manufacturer. I like Lapua and Norma. I first neck size the new brass then trim to length and finally turn the necks. I don't care about case weight or volume until it's fire formed so I load at starting loads and choose a heavy bullet. Once it's been once fired it is dedicated to that gun and I can sort by volume with water. I have a piece of plexiglass that I've drilled to match the holes in my ammo block, I fill the ammo block with the fireformed brass that still has the primers in them, put the plexiglass over the necks and then fill them with water. Once full, I remove the plexiglass and then weigh them to get the volume in grains and sort them. When I'm done, whichever group has the largest number of like cases is the one I use for load development. While it doesn't always hold true from lot to lot it generally says that majority group is the manufacturers target volume and when you buy more brass the majority of those should be in that same group.

It's important to remember that your are not precision reloading to achieve "good enough" and not every step is going to make a difference. It's the combination of all the steps taken that makes the difference. Each one, no matter how slight in significance, is important to the end product.

I guess I had that coming. LOL.

Brass sorting can be carried as far as you like.  
Plinking rounds, you don't want any that were misformed like a thinner web or something, but sorting ain't gonna be worth the time.  
Super Duper long range rounds, maybe a closer sorting.

Some might not realize that with a large enough sample you WILL get one that probably shouldn't have been sold.

Here's a small sample of some 62gr 22 Nosler (mostly the same headstamp ) brand new cartridges.
Notice the weight range in the pic, and rest assured that is NOT because of bullet or powder or primer.  
I can see 3 cartridges that get marked and culled after I shoot them for dummy or gauging rounds.
The rest (probably even just the 207 and 208gr) will be processed as once fired and reloaded (with heavier bullets) for competition.
ALL of them will probably shoot just fine @ 100yds.

Meh, I sort my brass, just like a lot of my other reloading techniques I am sure the "experts" would scoff at..When they start paying for/producing my ammo for me, then they can decide what steps are done in the process of producing my ammo....

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Next time I go shoot  6.8 I'll take those culls and measure the volume of the once shot extremes.  
I want to see how they group with the others.

Do you adjust your load based on the sorted cases? Have you noticed a measurable difference in their precision/POI?  If the answer is No or I’m not sure, you may want to at least evaluate the need for doing it (sorting by weight).

Some consider it a waste of time.  
I have found tighter extreme spreads in velocity with .30-06 cases sorted by weight, 6.5x55, and 7.62X39.  
It would take one heck of a velocity change to see anything at 100 yds or less.

I've seen all kinds of charts that showed weight just did not relate to volume.  I can find a 1:3 or 1:4 volume to weight relationship in same brand/headstamp cases.

I doubt anyone will say that a few percent difference in volume doesn't matter.  
Take 7% between the .223 and the .223AI.  Volume make any difference there?

One of my recent adventures, the 22 Nosler, where volume a 3% difference between a 22 Nosler case and a neck down 6mm Hagar case (22NOSGAR :) ) needs different loads.  If 3% to 7% makes a difference, would a 1% difference in VOLUME matter? Pick a value.
Here's the 22 Nosler case (average weight) compared to a 22 NOSGAR case. The head configuration accounts for most of the weight difference but the 3% volume difference DOES need different loads. Fired/sized cases. Same barrel, same die. One uses 5.56 bolt the other a 6.8 bolt.

NOTE: Would never actually load 35gr of CFE223.

If I'm loading 300 to 500 rounds for a range day I'll pull cases at random.
If I'm loading 60+ a few rounds for a competition, you can bet they will be as same as possible.  
If my POA is the center of the X (no wind :) ) 1/4 MOA low is on the line and still an X.  
Maybe someday Lapua will make some 22 Nosler cases.

Sorry, didn't directly answer your question
Do you adjust your load based on the sorted cases?

No.  Sort, shoot in weight groups, cull the really odd ones after plinking with them.

Question: Do you sort by number of firings?  Like new unfired cases, once fired, 6th fired ?
Do you find a volume difference between New processed brass and once fired?

_{BTW AKSnowRider That's just anal}

Yes, I keep cases sorted by the number of firings. Since I don’t anneal regularly, I’ve found that it impacts neck tension. If I’m not annealing, I’ll use 4x and beyond fired brass for tactical matches. I’m not worried if I lose them.

I never worry about volume within quality brass. Work up a load and that’s what I’ll run with that brass. If switching brass, it’s a new load. This method does ok for my application.

Looks like you have it dialed it. Vertical is TIGHT.
Down to the tenth of a grain.

That 100yds?
Never mind, I see that it is 100yds.  Converted the grid and MOA calculations to mils, then to cm then back to inches.

LOL.. it might be, but where I notice the difference is in ES and SD.. the more things I pay attention to, the more it closes up and the more consistent the ammo seems to be..

These 3 groups were all shot on the same day/same load methods/same rifle..only difference is the first group was random cases from across the sort...

#

FPS  FT-LBS

PF
5    3206    5250.13  737.38  
4    3259    5425.15  749.57  
3    3234    5342.24  743.82  
2    3222    5302.67  741.06  
1    3242    5368.70  745.66  
Average: 3232.6 FPS
SD: 20.0 FPS
Min: 3206 FPS
Max: 3259 FPS
Spread: 53 FPS
True MV: 3238 FPS

This group was with in 1 grain on case weight...
#

FPS  FT-LBS

PF
5    3218    5289.51  740.14  
4    3221    5299.38  740.83  
3    3214    5276.37  739.22  
2    3208    5256.69  737.84  
1    3214    5276.37  739.22  
Average: 3215.0 FPS
SD: 4.9 FPS
Min: 3208 FPS
Max: 3221 FPS
Spread: 13 FPS
True MV: 3220 FPS

And this group was down to the same case weight to the tenth...Drop the one outlier and this would be a fantastic group...
#

FPS  FT-LBS

PF
5    3231    5332.33  743.13  
4    3210    5263.24  738.30  
3    3214    5276.37  739.22  
2    3212    5269.80  738.76  
1    3216    5282.94  739.68  
Average: 3216.6 FPS
SD: 8.4 FPS
Min: 3210 FPS
Max: 3231 FPS
Spread: 21 FPS
True MV: 3222 FPS

Is any of this life and death changing in regard to everyday loads...nope... just one small thing that might contribute too making a better hit way out there..or maybe it won't..but it only takes me a few minutes to sort them...

Glad you didn't take offense at my dig :)

I like to think keeping charges to less than .5%, bullet weight to less than .5%, and
case weights to less than 1% might help.  Why?  MIGHT make a difference and keeping things at those levels of precision
doesn't seem to be that difficult.  Once you sort, they don't change much.  
At least you KNOW you don't have any odd ball cases.
If you don't weigh how do you know?  
I know, pick quality brass.

Nope, the dig made me lol.. I do this shit for fun...(and to fill the freezer with meat), I enjoy both the reloading and the shooting...Wait till they find out I anneal twice per reloading.. they are really gonna freak...

I know you are worried about the 1 outlier in the group measured to the tenth, but that’s part of what we’re saying. Also, the cases that varied by 1 gr had better std. dev/ ES. Even if you subtract 1 outlier from both, they are very close.

The 1 sample at random had 2 high velocities. With a larger sample size, you very well could see that in cases down to the 1 gr or tenth. Outliers if you will.

But, it’s your ammo. Nothing wrong with what you’re doing, but not everyone has the extra time for extra steps. I have to load for myself and my girlfriend. That’s close to 500rds for a big match, so the fewer steps the better. To top it off, my daughter is getting into it now. I’ll need to quit my job before long to load for them!

Yea. 100yds off a bipod and small rear squeeze bag. Std. Was 6.7fps over 10 shots. Taking it out this weekend to see how it does beyond 800yds. It should go transonic around 930-950yds.

Man, I wish I could buy brass with weights +/- 1/4 % and not have to cull out any.

You realize that’s the charge weight, right?

Of course, but I could see the same kind of differences in powder charge as well, or in neck tension or many other reasons, doesn't stop me from tracking those measurements either..

No, I was talking about that OCD brass sorting .
268.7grains +/- 0.25% is 268.0 to 269.4grains.

I try to keep my powder charges for the 22N to +/- 0.01 carats

Well shit man, after this left me sitting home on my ass everyday its either sit on the computer or screw around at the loading bench...

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And I was going to complain about not being able to go shoot this weekend because the range is flooded.

Shit, I wish I could go shoot everyday..don't feel good enough most of the time,,, heck if I am lucky I get to shoot twice a month..most of the time its only once a month..plus closest range only goes to 300 yards..pretty short..To hit a 1000 I have to drive 3 hours each way.. or go out to the cabin. which is 3 hrs on the road and 6 hrs in a buggy..