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sorting by empty case weight?

Just because the different brands doesn't matter, the math is the same as the exterior dimensions are the same.


No, not saying they are incorrect at all. In fact, they still support the hypotheses for the correlation between weight and case volume. Though I don't have the actual raw data to draw the slope, I can still draw an estimated slope of those data points where you can see the relationship for weight and volume.

And BTW, it would have been better data had the weights no include the primers as the primers have some variance too; as well as the data being a small set. ;)

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I've measured case weights and volumes using plugs; no statistical difference. i.e. the spent primer weight-to-weight variation is statistically insignificant.

Here are my plots showing the trend line and the "R-Squared". The R-Squared is a statistical calculation that determines how good the data correlates. A value of 1.0 is a perfect correlation and 0.0 means there's absolutely no correlation. For reference, in soft sciences like social sciences, a value of 0.2 - 0.4 is considered good. In pure sciences, a value of 0.6 is considered good. The R-Squared results I got are too small to indicate any correlations between case + spent primer weight and case capacity.

I have a lot more data, including on Nosler cases, but it all led me down the same pathway...........there isn't a statistical correlation between weights and capacities.

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I'm not any sort of competitive shooter, but I like finding repeatable precision in all my reloading, for building up my first shot/cold barrel confidence (...I loathed getting the deer-camp nick-name of "two-shots").

My question is; what sort of variance are you allowing when sorting for empty case weights, as a way of gauging consistent internal case capacity?

Thanks for sharing your experience,
I think with deer camp rifles, like any rifle, it comes down to doing the same thing every time for repeatable results.

I sorted out a friend’s Douglas barreled 300 win mag a couple years ago. He said it had initially been a 1/2 inch rifle at 100 yards when new, and for years. He said it had gotten to be a several inch rifle the past couple of years; causing him to miss deer. In quizzing him, he thought he was around 800 rounds on it. He’d been using the same 2 loads since new, depending on which bullet he was shooting. A thorough cleaning showed no carbon ring, not terrible throat wear.

I took it to shoot it, along with a handful of ammo he had loaded. As I was getting ready, I noticed several headstamps. I stopped and called him and started quizzing him again.

He’d been using whatever cases he had on hand. The case capacity difference between the various mfrs. was causing the spread in accuracy for his formerly reliable load. Granted, that’s an extreme example of weight affecting accuracy, but the principle is the same.

Got new cases, weight sorted them and sorted bullets, did a load development, and got the rifle back shooting where it needed to be.
 
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I do sort Lapua brass for bigger matches. It does make a difference. I receive 3fps spread in a 10 shot string. It does make a difference on paper. But I am not a competitive shooter, so it really doesn’t matter, does it?
 
I'm not any sort of competitive shooter, but I like finding repeatable precision in all my reloading, for building up my first shot/cold barrel confidence (...I loathed getting the deer-camp nick-name of "two-shots").

The best way to ensure first shot hits is to spend your time practicing shooting in those conditions, not sorting your brass, bullets, or weighing your powder charges with a tweezers.

You didn't mention what your rifle is chambered in, but since you mentioned "deer camp" and your location is NY, my opinion is that if it is anything larger than 308, it is unnecessary. Shooting a 7RM at whitetails that are 200 yards away doesn't lend itself to precision. First, and largest, reason is because most people don't practice enough with those bigger cartridges to ensure precision. Having a similar rifle setup chambered in a much smaller cartridge, such as .223, can be very helpful as you can practice your mechanics and build muscle memory with your "trainer", but you will never be able to replicate the light recoil of that trainer with your hunting rifle. Also, since NY is a commie state, they won't let you have a suppressor, which also helps tremendously.

Now, if you do have a 308, 7-08, 243, etc, then get out there and practice like you hunt. Get off the bench, simulate shooting from the ground, or a tree stand. Elevate your heart-rate and shoot to help simulate that "buck-fever" coming on. I can guarantee that if you put a few hundred rounds downrange doing those drills prior to the season, your first round hit rate will increase significantly.
 
So in this thread you see examples that case weight variation within one grain have little to no effect on case capacity. If you do a search you will find sorts exhibiting variability of several grains which subsequently do translate to correlating capacity differences, which has also been my experience even with Lapua. Unless you weigh brass, you don't know which camp you're in; or in the words of Clint Eastwood " do you feel lucky today punk".
 
The best way to ensure first shot hits is to spend your time practicing shooting in those conditions, not sorting your brass, bullets, or weighing your powder charges with a tweezers.

You didn't mention what your rifle is chambered in, but since you mentioned "deer camp" and your location is NY, my opinion is that if it is anything larger than 308, it is unnecessary. Shooting a 7RM at whitetails that are 200 yards away doesn't lend itself to precision. First, and largest, reason is because most people don't practice enough with those bigger cartridges to ensure precision. Having a similar rifle setup chambered in a much smaller cartridge, such as .223, can be very helpful as you can practice your mechanics and build muscle memory with your "trainer", but you will never be able to replicate the light recoil of that trainer with your hunting rifle. Also, since NY is a commie state, they won't let you have a suppressor, which also helps tremendously.

Now, if you do have a 308, 7-08, 243, etc, then get out there and practice like you hunt. Get off the bench, simulate shooting from the ground, or a tree stand. Elevate your heart-rate and shoot to help simulate that "buck-fever" coming on. I can guarantee that if you put a few hundred rounds downrange doing those drills prior to the season, your first round h
+1 for everything said here
And the mentality "There is no replacement for displacement" is for drag racing
Not for hunting within 300 yds.
------------------------------------------------
I will add also, as far as First round hits...
There can be a big difference in point of impact between
Shooting off a Bench
And Shooting from the Shoulder
-----------------------------------------------
As much as 6 inches difference
So a guy that thinks he has sighted in off the bipod on the bench is good to go
May miss by 6 inches when shooting from the rifle shouldered
Practice and sight in using the exact method you will actually be hunting
----------------------------------------------
When you never shoot 5 shot groups larger than 1/2" at 100 yds
...then I would consider weight sorting cases or bullets
 
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I appreciate all your suggestions about "practical" precision, all very true and practiced in my non-competitive experience too.

And to qualify my latent obsession with precision in my reloading practices, it comes from my also-latent practical shooting practice of; "aim small = miss small" , and "DON'T practice missing" .

These on-line discussions help me focus, slow my heart rate and breathing, and give me time to reconsider my target, before I pull the trigger,
 
I'm not any sort of competitive shooter, but I like finding repeatable precision in all my reloading, for building up my first shot/cold barrel confidence (...I loathed getting the deer-camp nick-name of "two-shots").

My question is; what sort of variance are you allowing when sorting for empty case weights, as a way of gauging consistent internal case capacity?

Thanks for sharing your experience,
This subject has been covered a 100 times. Do a keyword search.
 
Cold bore shot = buck fever
COLD BARREL SHOT = BUCK DOWN
All of my big game have gone down hard clear out to 574 yards with one shot kills!!!
All but one!!! A bullet grenaded on a huge bucks rib, blowing out that lung on that side with a 25-06 at 325!!! Finished him off at around 525 when he turned to look around and figure out what happened!!!
My son has had one multiple shot kill, the rest were one and down!!!
I sort cases by velocity after one shot case fire forming and case prep!!!
Bullets and primers are bin sorted!!!!
 
What is minute of deer accuracy .5, 1, 1.5, 2 moa? Asking for a friend.
Depends on the range of the rifle, load, and shooter!!!!
If you have a .5MOA, you are capable of hitting the deer heart at 500, as long as you practice on targets at various ranges out to 500!!!!
If you are limiting yourself to 200, that 2.5inch deer heart hit requires 1.25MOA!!!
At just 100 yards max, requires 2.5MOA!!!
SIMPLE RELATED TRIANGLES!!!!
 
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Look for the Erik Cortina hunting challenge on youtube..very very few shooters hit a deer heart at 500 and most trying it use competition long range rifle not hunting rig.
On top of it - they have all the time in the world to get set up…good weather. If it’s rarely done at 500 in perfect condition..it just not happen very often in real hunting.

Back on subject..sorting bullet have an effect on target..sorting quality case like Lapua is a waste of time and only has an effect in the reloader’s mind.
 
I met a guy at a range one time that was very proud that he wore clean white cotton gloves when he set bullets in the case mouth to seat as to not get any oils from his skin on his bullets to affect accuracy.. True story.
Ah! Maybe a class 100 clean room also - no foreign particles.
 
f you are limiting yourself to 200, that 2.5inch deer heart hit requires 1.25MOA!!!
I'll throw a scenario out with that 1.25 MOA at 200. Your climbing a hill got some cross wind, breathing going on a good buck jumps up in front of you and now you got a little buck fever going on now whats your 1.25 MOA like you had at the range?
Or a buck or bull of a lifetime presents itself at 400 now is that 1.25 MOA with the above conditions now what do you do with your 1.25 MOA gun?
These minute of deer guns are never that in hunting conditions there not the same as at the range.
 
I did an experiment several years ago to determine just how much effect brass weight has on .223 loads. I used WW brass (sized, trimmed and deburred, primer pockets uniformed, flash holes deburred, and neck turned) , WSR primers, charges of RL-15 or N-550 powder weighed to 0.1 gr, and 75 gr A-Max bullets. Using the lightest and heaviest cases (sorted from 1000 once-fired I had on hand), I had two lots of 10 cases with a 3 gr difference in weight. The average muzzle velocity difference was 16 fps, just a bit more than the 12 fps due to 0.1 gr of powder. I choose to sort 0.5 gr lots of .223 brass for my long range loads, but the effect will only matter at 800-1000 yards - the vertical displacement on the target from such a small velocity change is negligible at shorter distances. Unless you control all other sources of variation, the effect of brass weight is negligible. I also shoot .284, and because the brass is twice as heavy I batch in 1 gr lots.
 

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