Sorting Brass and Bullets?

[J E Custom]

Thanks again for all the replies.

And just to clarify, when I asked how much it would take to see a difference on paper I didn't mean changing the charge at all but using the same charge in cases with different capacities. I know in theory a case with the same charge but less capacity will produce higher pressure. I was asking at what point would this be noticeable, 1-2 gr difference in case capacity, more, less?

When I sort, I Hold all cases to within one grain for general hunting and for accuracy testing, I try to match all cases used to the same volume/weight. the cases that are within 1 grain shoot well but the ones that are the same shoot better.

The last time I tested the results were=

Zero differences in capacity = .071 for 5 shots@ 100 yards.
One grain sort = .092 for 5 shots @ 100 yards.
The cases that were out of the sort tolerance (I use them for break in or fouling) = .290 5 shots

Some of this is/was probably me, but the differences are noticeable.

While sorting, I keep different batches separate for loading and find that some tweaking is necessary to get the same accuracy/velocity when I change to a different batch by upping or dropping the powder charge by 10ths of a grain.

I cant tell you how much volume change because it varies from cartridge to cartridge, but I can say that if everything is the same there is a difference in accuracy and SDs.

J E CUSTOM

 

[Lonewolf74]

Thanks again for all the info guy's definitely giving me things to think about and consider when tweaking and trying to find the best accuracy I can. Now I just wish I had more time to test and tinker with things.

 

[Lonewolf74]

On a slightly different note, something brass prep made me think about, is there a way to measure and accurately determine what length I can leave the necks for my particular rifles? For example if I'm remembering numbers correctly the max case length for a 300 win mag is 2.620 and trim to length is 2.610 but say in my rifle it can fit 2.630 so I would trim them to 2.625 or so to keep tolerance tight. This is just an example and it could be more or less than this in my rifle but how do I figure this out?

 

[Mikecr]

Sinclair has a tool for this.
It's basically a plug you long seat in a case that you've over-trimmed(sacrificial). You chamber the round with this, and your chamber end seats the plug deeper. Extract the test round and measure for max case OAL.

If I can, I trim new brass to 0(right at max). When I fire the cases the necks pull back from a few thou up to 10thou depending on how much new shoulder angles pull them back. If they're consistent at that point, and under 5thou clearance, I'll re-trim to same length. Until then I don't trim again.
-5thou is a really good place. It reduces sooting seen on necks, which will usually lead to lower SD, and it pretty much eliminates carbon ring formation. But most folks don't manage trim length that close. Doing so with older cartridge designs, requiring more sizing, can be a continual chore.

I do not subscribe to trimming cases to same length, just for the sake of that, where it leads to excessive end clearance. I see that as another example(there are many) of counter productive actions people take, with assumptions that they're improving things.

 

[Lonewolf74]

Thanks Mike that is what I have in mind just wasn't sure how to get there, at the moment I only trim .005 under max case length but I knew there had to be a way to figure it out more precise for my rifle.

So to make sure I understood, you first set the length to 0 or max length. Then they will shrink some on firing but as long as they stay under .005 clearance you'll trim them all to the same length within that .005 clearance. Say they all shrank to between .001-.003 so you would trim them to all .003 clearance to keep same? On the other hand if they shrank .006-.008 you would not trim till they have expanded to 0 or within .005?

 

[jimbires]

these are the tools Mike is talking about . I use them too , they work .


SINCLAIR INTERNATIONAL Sinclair Chamber Length Gage | Sinclair Intl

 

[Mikecr]

Lonewolf74, Yes you got it. And my 0, is my measured 0.

Many reloaders just trim all cases to 'book' range, regardless of their own chambers, typically at shortest of their brass on-hand. That's the opposite of making good ammo.

To separate diamonds from dirt, you should first understand the difference, and second, accepting that dirt is worthless.
Toss the worst, use the best, so often that it no longer bothers you.

 

[Lonewolf74]

Thanks again for all the info...this reloading stuff kind of makes my head spin sometimes! And thanks for the link I'm gonna order a couple of them for sure

 

[Trnelson]

Thanks again for all the info...this reloading stuff kind of makes my head spin sometimes! And thanks for the link I'm gonna order a couple of them for sure

Yep. Keep a journal on your bench record every detail you can about the ammo. I also keep a journal for each rifle I have to track results, cleaning schedules ect... A journal answers all those detail questions you can't possibly remember, especially if there are multiple rifles in the mix. Was the brass annealed last time or two times ago or ever? What is the weight of fully prepared empty cases? How did it shoot? It helps in backtracking problems as well. I tried this and this and got that result so now I want to try this...accuracy is an interconnected system that starts with knowing and controlling the details you need to achieve the results you desire. Oh and practice. Lots of practice. Have fun and be safe!

 

[Steve Sheasly]

You are correct. Weighing brass is just stupid. The reason for weighing is to check volume. Volume in a case affects the burn rate and how the powder is burned. But weight does not tell you about volume. I took two identical .338 Lapua Mag. Norma brass, they are exactly the same in weight and all other measurements. But instead of using water or other medium I used the powder H-1000 and tamped each case with the same pressure. One case held 134.1 grains and the other case held 144.0 grains of powder I was surprised so I did the test on other cases that I had primed and ready to load. The volumes were different in several cases. Mostly the Hornady Brass. So I ordered 100 brass cases from Brownells all Lapua brass. I have never spent this kind of money before on brass but I am confident it will be worth it. I am a hunter not a bench rest person. But I make very long shots. My closest shot last year was 500 yards. When you spend a lot of money on a trip the last thing you want to worry about is where is the bullet going to hit. I do not need a one hole gun but I want to shoot sub MOA. Your comments are right on.

I agree with almost everything said except that weighing doesn't do any good.

I started out volume testing when I started trying to improve accuracy and used as many mediums
as possible even making up a solution with a wetting agent that would eliminate surface tension.

I also used alcohol and other cleaning agents. that all worked well except for the mess and storage
of these products. Also I tried different powders, (Mostly ball powders because they measure good) I also used all of the latest tools to measure volume. (Buret)

I decided to evaluate weighting and see how effective/accurate it was compared to volume testing. I found that if I totally prepped the brass as mentioned, and the outside was dimensionally consistent/the same before it was fired, it was very accurate. I also like the fired cases idea because it is probably the best chance of getting the outside of the case dimensionally the same and as long as you trim to length, and de-cap the primer. Spent primers sometimes gave me different volumes in the same case and all I could figure was that they sometimes held a bubble, so I de-caped and reversed the primer to seal the primer pocket for better/more consistent results. This added time and effort to the process of volume testing.

Even though time is not a problem for me, and my philosophy is "No matter what it takes", If I can streamline a process and get as good or better results I will. and weight sorting does this as long as total case prep is done before weighing.

There is a very simple explanation why it works if done right. If the brass is dimensionally identical on the outside,
the only thing that can change the weight is brass thickness. if it is heavier, the brass thickness is greater. If it is lighter the brass thickness thinner. Lighter brass, more volume. heaver brass, less volume. Simple.

What I found in comparing the two processes, They can both be very accurate if good procedures are used before the actual test is performed. The difference between doing which ever process you want to and not doing anything can definitely be measured in accuracy. the difference between the two if both are done right, cant.

The bullet checking is another part of the consistency process but it does have an effect on the case volume. This is the reason I verify the consistency of the bullet base to the Ojive. if this dimension is not the same, when the bullet is seated using the bullet seater it makes contact and presses on the Ojive. if the dimension is different the base of the bullet is in a slightly different place in the case and can change the case volume slightly. This change may be miniscule, but it is all part of making everything as consistent as possible. bullet prep can also increase the accuracy of a rifle if the shooter has the desire to improve the accuracy.

I totally agree that under real hunting conditions many of the accuracy procedures cannot be measured because of shooter error, but in a bench test environment they can easily improve accuracy and consistency (SDs and ESs).

Just my opinion based on over 50 years of shooting and loading accuracy ammo.

J E CUSTOM