weighing cases

[Regnar]

After reading a few threads about doing the little things, i have decided to stsrt weighing cases. my questios are:

1. what is the most effieient way to measure intetnal volume? powder? water? what?

2. what spread to you sort to?

 

[Keith Glasscock]

Give it 6 months, then ask again... The easy way is being invented right now.

 

[retired]

i use 77* water for volume
i weight sort in .1 gr steps

 

[T-shooter]

Weighing is better than nothing. It far from being exact but if there is a large enough volume change it will show up. Probably best to weigh with water with a drop of soap to break the surface tension. 21st Century makes a plug that uses a tiny o-ring to seal the primer pocket. I use a slight touch of grease on the o-ring for lubrication. Weigh the dry case and plug, zero the scale, fill, and reweigh. It you fill to get a slight crown of water you can wick off a tiny bit with the edge of a paper towel if necessary. All your brass should be resized and trimmed to length first.

 

[Regnar]

Give it 6 months, then ask again... The easy way is being invented right now.

Didnt ask the easy way

 

[Regnar]

Thanks

 

[retired]

actually a tissue/kleenex is a finer method of wicking off a bit of water

 

[tenring]

1038884[/ATTACH]View attachment 1038885

I weigh brass just as it come out of the box. By first trimming, you will induce weight variations.

 

[Regnar]

I weigh brass just as it come out of the box. By first trimming, you will induce weight variations.

Am not asking how to weigh brass.

 

[retired]

and you are lost
things that vary weight but not internal volume
trim to length..all necks should be the same
neck turning..its out side but affects weight not vol
uniform primer pocket..i use a reverse seated primer.removes weight but not vol

internal flash hole debur...both weight and vol.
all should b done before weight sort.
some say fire once then do all this.

I weigh brass just as it come out of the box. By first trimming, you will induce weight variations.

 

[JRS]

Use fired, unsized brass… water, and a reliable, repeatable scale.

 

[Ned Ludd]

Determining case volume with water is not that difficult an exercise, but it takes a fair amount of time if you plan to do it for all the cases you intend to load and fire:

http://forum.accurateshooter.com/threads/case-volume-determination-pic-heavy.3896148/

There are caveats to using case weight alone to sort brass, as has been noted above. Case length, width/depth of the extractor groove, and base-to-shoulder dimensions are all factors that will affect case volume without altering case weight. I've sorted many, many cases by weight where I also determined case water volume and plotted the results. If case weight was always perfectly proportional to case volume, each of the case weight versus case volume values would lie exactly on a straight line with a negative slope, which is not what is normally observed. You will usually find some outliers where cases sorted by weight alone exhibit a volume estimate value that is well off the curve of case weight versus case volume, as determined using water weight. Nonetheless, sorting cases by weight alone will almost always give you much more consistent internal volume in your sorting groups than not sorting at all. Only you can decide whether your shooting needs and available time require/allow you to do the extra diligence necessary to sort cases by water volume.

FWIW - I shoot in F-TR and will likely never see the effect on the target of minor variance in case volume that arises from sorting cases by weight; it is simply not the limiting factor in terms of precision for what I do. So I typically determine water volume for 20 cases or so from each brass prep to obtain an average case volume value for use with QuickLoad, then sort cases by weight when loading for a match.

 

[Rope2horns]

Didnt ask the easy way

I think you misunderstood what Keith was trying to explain.....someone is working on a easy (more efficient) way to measure case capacity as we speak.

 

[retired]

unsized brass is not what you will be loading in spite the fact that quickload uses that volume.
i have never seen quickload vol correct for my brass.
do as you choose

Use fired, unsized brass… water, and a reliable, repeatable scale.

 

[Regnar]

I think you misunderstood what Keith was trying to explain.....someone is working on a easy (more efficient) way to measure case capacity as we speak.

Well is thats the case (pun intended) i did take it wrong and will eagerly await the new method. any hints as to what direction?

 

[Regnar]

Determining case volume with water is not that difficult an exercise, but it takes a fair amount of time if you plan to do it for all the cases you intend to load and fire:

http://forum.accurateshooter.com/threads/case-volume-determination-pic-heavy.3896148/

There are caveats to using case weight alone to sort brass, as has been noted above. Case length, width/depth of the extractor groove, and base-to-shoulder dimensions are all factors that will affect case volume without altering case weight. I've sorted many, many cases by weight where I also determined case water volume and plotted the results. If case weight was always perfectly proportional to case volume, each of the case weight versus case volume values would lie exactly on a straight line with a negative slope, which is not what is normally observed. You will usually find some outliers where cases sorted by weight alone exhibit a volume estimate value that is well off the curve of case weight versus case volume, as determined using water weight. Nonetheless, sorting cases by weight alone will almost always give you much more consistent internal volume in your sorting groups than not sorting at all. Only you can decide whether your shooting needs and available time require/allow you to do the extra diligence necessary to sort cases by water volume.

FWIW - I shoot in F-TR and will likely never see the effect on the target of minor variance in case volume that arises from sorting cases by weight; it is simply not the limiting factor in terms of precision for what I do. So I typically determine water volume for 20 cases or so from each brass prep to obtain an average case volume value for use with QuickLoad, then sort cases by weight when loading for a match.

Ao you weighing a few case with water. do you adjust your charge according to that volume? or do you simply weigh cases and sort by that?

 

[Marksman63]

Ao you weighing a few case with water. do you adjust your charge according to that volume? or do you simply weigh cases and sort by that?

In Quickload you do this

 

[spife7980]

Well is thats the case (pun intended) i did take it wrong and will eagerly await the new method. any hints as to what direction?

Supposedly its a puffer that will measure air pressure/volume or something to that extent from the bread crumb a couple months back? If thats whats being referred to above http://forum.accurateshooter.com/threads/digital-case-volume-meter.3937716/#post-37086014

 

[Bart B.]

How much does case headspace spread and out of round body and neck have on the space inside them?

Do both an ellipse and circle with the same circumference have the same area?

 

[Regnar]

I fairley new to this game, actually very new compared to most of you. ive never used quick loads. what will quick loads do for me that I cant do with out it which relates to reloading? if I dont have it is it worth measuring internal volume and sorting?

I reload for lr accuracy on three calibers, 6.5 creed, 6.5 lapua and 6 br.